diff --git a/Example.ipynb b/Example.ipynb
index ec50dd4..0ad1858 100644
--- a/Example.ipynb
+++ b/Example.ipynb
@@ -2,7 +2,7 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 1,
    "id": "53bc9780",
    "metadata": {},
    "outputs": [],
@@ -14,7 +14,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 2,
    "id": "1f3871fc",
    "metadata": {},
    "outputs": [],
@@ -24,7 +24,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 3,
    "id": "6fd7e7f9",
    "metadata": {},
    "outputs": [
@@ -50,7 +50,7 @@
        "}"
       ]
      },
-     "execution_count": 2,
+     "execution_count": 3,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -62,252 +62,128 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "id": "3dd386bd",
+   "execution_count": 6,
+   "id": "b77ff62c",
    "metadata": {},
    "outputs": [
     {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "131\n"
-     ]
-    },
-    {
-     "ename": "IndexError",
-     "evalue": "positional indexers are out-of-bounds",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mIndexError\u001b[0m                                Traceback (most recent call last)",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/indexing.py:1714\u001b[0m, in \u001b[0;36m_iLocIndexer._get_list_axis\u001b[0;34m(self, key, axis)\u001b[0m\n\u001b[1;32m   1713\u001b[0m \u001b[38;5;28;01mtry\u001b[39;00m:\n\u001b[0;32m-> 1714\u001b[0m     \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mobj\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43m_take_with_is_copy\u001b[49m\u001b[43m(\u001b[49m\u001b[43mkey\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43maxis\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43maxis\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m   1715\u001b[0m \u001b[38;5;28;01mexcept\u001b[39;00m \u001b[38;5;167;01mIndexError\u001b[39;00m \u001b[38;5;28;01mas\u001b[39;00m err:\n\u001b[1;32m   1716\u001b[0m     \u001b[38;5;66;03m# re-raise with different error message, e.g. test_getitem_ndarray_3d\u001b[39;00m\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/generic.py:4153\u001b[0m, in \u001b[0;36mNDFrame._take_with_is_copy\u001b[0;34m(self, indices, axis)\u001b[0m\n\u001b[1;32m   4144\u001b[0m \u001b[38;5;250m\u001b[39m\u001b[38;5;124;03m\"\"\"\u001b[39;00m\n\u001b[1;32m   4145\u001b[0m \u001b[38;5;124;03mInternal version of the `take` method that sets the `_is_copy`\u001b[39;00m\n\u001b[1;32m   4146\u001b[0m \u001b[38;5;124;03mattribute to keep track of the parent dataframe (using in indexing\u001b[39;00m\n\u001b[0;32m   (...)\u001b[0m\n\u001b[1;32m   4151\u001b[0m \u001b[38;5;124;03mSee the docstring of `take` for full explanation of the parameters.\u001b[39;00m\n\u001b[1;32m   4152\u001b[0m \u001b[38;5;124;03m\"\"\"\u001b[39;00m\n\u001b[0;32m-> 4153\u001b[0m result \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mtake\u001b[49m\u001b[43m(\u001b[49m\u001b[43mindices\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mindices\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43maxis\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43maxis\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m   4154\u001b[0m \u001b[38;5;66;03m# Maybe set copy if we didn't actually change the index.\u001b[39;00m\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/generic.py:4133\u001b[0m, in \u001b[0;36mNDFrame.take\u001b[0;34m(self, indices, axis, **kwargs)\u001b[0m\n\u001b[1;32m   4129\u001b[0m     indices \u001b[38;5;241m=\u001b[39m np\u001b[38;5;241m.\u001b[39marange(\n\u001b[1;32m   4130\u001b[0m         indices\u001b[38;5;241m.\u001b[39mstart, indices\u001b[38;5;241m.\u001b[39mstop, indices\u001b[38;5;241m.\u001b[39mstep, dtype\u001b[38;5;241m=\u001b[39mnp\u001b[38;5;241m.\u001b[39mintp\n\u001b[1;32m   4131\u001b[0m     )\n\u001b[0;32m-> 4133\u001b[0m new_data \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43m_mgr\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mtake\u001b[49m\u001b[43m(\u001b[49m\n\u001b[1;32m   4134\u001b[0m \u001b[43m    \u001b[49m\u001b[43mindices\u001b[49m\u001b[43m,\u001b[49m\n\u001b[1;32m   4135\u001b[0m \u001b[43m    \u001b[49m\u001b[43maxis\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43m_get_block_manager_axis\u001b[49m\u001b[43m(\u001b[49m\u001b[43maxis\u001b[49m\u001b[43m)\u001b[49m\u001b[43m,\u001b[49m\n\u001b[1;32m   4136\u001b[0m \u001b[43m    \u001b[49m\u001b[43mverify\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[38;5;28;43;01mTrue\u001b[39;49;00m\u001b[43m,\u001b[49m\n\u001b[1;32m   4137\u001b[0m \u001b[43m\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m   4138\u001b[0m \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39m_constructor_from_mgr(new_data, axes\u001b[38;5;241m=\u001b[39mnew_data\u001b[38;5;241m.\u001b[39maxes)\u001b[38;5;241m.\u001b[39m__finalize__(\n\u001b[1;32m   4139\u001b[0m     \u001b[38;5;28mself\u001b[39m, method\u001b[38;5;241m=\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mtake\u001b[39m\u001b[38;5;124m\"\u001b[39m\n\u001b[1;32m   4140\u001b[0m )\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/internals/managers.py:891\u001b[0m, in \u001b[0;36mBaseBlockManager.take\u001b[0;34m(self, indexer, axis, verify)\u001b[0m\n\u001b[1;32m    890\u001b[0m n \u001b[38;5;241m=\u001b[39m \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39mshape[axis]\n\u001b[0;32m--> 891\u001b[0m indexer \u001b[38;5;241m=\u001b[39m \u001b[43mmaybe_convert_indices\u001b[49m\u001b[43m(\u001b[49m\u001b[43mindexer\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mn\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mverify\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mverify\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m    893\u001b[0m new_labels \u001b[38;5;241m=\u001b[39m \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39maxes[axis]\u001b[38;5;241m.\u001b[39mtake(indexer)\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/indexers/utils.py:282\u001b[0m, in \u001b[0;36mmaybe_convert_indices\u001b[0;34m(indices, n, verify)\u001b[0m\n\u001b[1;32m    281\u001b[0m     \u001b[38;5;28;01mif\u001b[39;00m mask\u001b[38;5;241m.\u001b[39many():\n\u001b[0;32m--> 282\u001b[0m         \u001b[38;5;28;01mraise\u001b[39;00m \u001b[38;5;167;01mIndexError\u001b[39;00m(\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mindices are out-of-bounds\u001b[39m\u001b[38;5;124m\"\u001b[39m)\n\u001b[1;32m    283\u001b[0m \u001b[38;5;28;01mreturn\u001b[39;00m indices\n",
-      "\u001b[0;31mIndexError\u001b[0m: indices are out-of-bounds",
-      "\nThe above exception was the direct cause of the following exception:\n",
-      "\u001b[0;31mIndexError\u001b[0m                                Traceback (most recent call last)",
-      "Cell \u001b[0;32mIn[3], line 1\u001b[0m\n\u001b[0;32m----> 1\u001b[0m Ta_C \u001b[38;5;241m=\u001b[39m \u001b[43mforecast_Ta_C\u001b[49m\u001b[43m(\u001b[49m\n\u001b[1;32m      2\u001b[0m \u001b[43m    \u001b[49m\u001b[43mtime_UTC\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[38;5;124;43m\"\u001b[39;49m\u001b[38;5;124;43m2025-05-22 21:11:22.358885\u001b[39;49m\u001b[38;5;124;43m\"\u001b[39;49m\u001b[43m,\u001b[49m\n\u001b[1;32m      3\u001b[0m \u001b[43m    \u001b[49m\u001b[43mgeometry\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mgeometry\u001b[49m\u001b[43m,\u001b[49m\n\u001b[1;32m      4\u001b[0m \u001b[43m)\u001b[49m\n\u001b[1;32m      6\u001b[0m Ta_C\n",
-      "File \u001b[0;32m~/Projects/global-forecasting-system/global_forecasting_system/global_forecasting_system.py:275\u001b[0m, in \u001b[0;36mforecast_Ta_C\u001b[0;34m(time_UTC, geometry, resampling, directory, listing)\u001b[0m\n\u001b[1;32m    269\u001b[0m \u001b[38;5;28;01mdef\u001b[39;00m\u001b[38;5;250m \u001b[39m\u001b[38;5;21mforecast_Ta_C\u001b[39m(\n\u001b[1;32m    270\u001b[0m         time_UTC: datetime,\n\u001b[1;32m    271\u001b[0m         geometry: rt\u001b[38;5;241m.\u001b[39mRasterGeometry \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m,\n\u001b[1;32m    272\u001b[0m         resampling: \u001b[38;5;28mstr\u001b[39m \u001b[38;5;241m=\u001b[39m \u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mcubic\u001b[39m\u001b[38;5;124m\"\u001b[39m,\n\u001b[1;32m    273\u001b[0m         directory: \u001b[38;5;28mstr\u001b[39m \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m,\n\u001b[1;32m    274\u001b[0m         listing: pd\u001b[38;5;241m.\u001b[39mDataFrame \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m) \u001b[38;5;241m-\u001b[39m\u001b[38;5;241m>\u001b[39m rt\u001b[38;5;241m.\u001b[39mRaster:\n\u001b[0;32m--> 275\u001b[0m     \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[43mforecast_Ta_K\u001b[49m\u001b[43m(\u001b[49m\u001b[43mtime_UTC\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mtime_UTC\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mgeometry\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mgeometry\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mresampling\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mresampling\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mdirectory\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mdirectory\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mlisting\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mlisting\u001b[49m\u001b[43m)\u001b[49m \u001b[38;5;241m-\u001b[39m \u001b[38;5;241m273.15\u001b[39m\n",
-      "File \u001b[0;32m~/Projects/global-forecasting-system/global_forecasting_system/global_forecasting_system.py:267\u001b[0m, in \u001b[0;36mforecast_Ta_K\u001b[0;34m(time_UTC, geometry, resampling, directory, listing)\u001b[0m\n\u001b[1;32m    261\u001b[0m \u001b[38;5;28;01mdef\u001b[39;00m\u001b[38;5;250m \u001b[39m\u001b[38;5;21mforecast_Ta_K\u001b[39m(\n\u001b[1;32m    262\u001b[0m         time_UTC: datetime,\n\u001b[1;32m    263\u001b[0m         geometry: rt\u001b[38;5;241m.\u001b[39mRasterGeometry \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m,\n\u001b[1;32m    264\u001b[0m         resampling: \u001b[38;5;28mstr\u001b[39m \u001b[38;5;241m=\u001b[39m \u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mcubic\u001b[39m\u001b[38;5;124m\"\u001b[39m,\n\u001b[1;32m    265\u001b[0m         directory: \u001b[38;5;28mstr\u001b[39m \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m,\n\u001b[1;32m    266\u001b[0m         listing: pd\u001b[38;5;241m.\u001b[39mDataFrame \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m) \u001b[38;5;241m-\u001b[39m\u001b[38;5;241m>\u001b[39m rt\u001b[38;5;241m.\u001b[39mRaster:\n\u001b[0;32m--> 267\u001b[0m     \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[43mGFS_interpolate\u001b[49m\u001b[43m(\u001b[49m\u001b[43mmessage\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mGFS_TA_MESSAGE\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mtime_UTC\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mtime_UTC\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mgeometry\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mgeometry\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mresampling\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mresampling\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mdirectory\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mdirectory\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mlisting\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mlisting\u001b[49m\u001b[43m)\u001b[49m\n",
-      "File \u001b[0;32m~/Projects/global-forecasting-system/global_forecasting_system/global_forecasting_system.py:225\u001b[0m, in \u001b[0;36mGFS_interpolate\u001b[0;34m(message, time_UTC, geometry, resampling, directory, listing)\u001b[0m\n\u001b[1;32m    218\u001b[0m \u001b[38;5;28;01mdef\u001b[39;00m\u001b[38;5;250m \u001b[39m\u001b[38;5;21mGFS_interpolate\u001b[39m(\n\u001b[1;32m    219\u001b[0m         message: \u001b[38;5;28mint\u001b[39m,\n\u001b[1;32m    220\u001b[0m         time_UTC: datetime,\n\u001b[0;32m   (...)\u001b[0m\n\u001b[1;32m    223\u001b[0m         directory: \u001b[38;5;28mstr\u001b[39m \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m,\n\u001b[1;32m    224\u001b[0m         listing: pd\u001b[38;5;241m.\u001b[39mDataFrame \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m) \u001b[38;5;241m-\u001b[39m\u001b[38;5;241m>\u001b[39m rt\u001b[38;5;241m.\u001b[39mRaster:\n\u001b[0;32m--> 225\u001b[0m     before_after \u001b[38;5;241m=\u001b[39m \u001b[43mGFS_before_after_addresses\u001b[49m\u001b[43m(\u001b[49m\u001b[43mtime_UTC\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mlisting\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mlisting\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m    227\u001b[0m     before_address \u001b[38;5;241m=\u001b[39m before_after\u001b[38;5;241m.\u001b[39miloc[\u001b[38;5;241m0\u001b[39m]\u001b[38;5;241m.\u001b[39maddress\n\u001b[1;32m    228\u001b[0m     logger\u001b[38;5;241m.\u001b[39minfo(\u001b[38;5;124mf\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mbefore URL: \u001b[39m\u001b[38;5;132;01m{\u001b[39;00mcolored_logging\u001b[38;5;241m.\u001b[39mURL(before_address)\u001b[38;5;132;01m}\u001b[39;00m\u001b[38;5;124m\"\u001b[39m)\n",
-      "File \u001b[0;32m~/Projects/global-forecasting-system/global_forecasting_system/global_forecasting_system.py:164\u001b[0m, in \u001b[0;36mGFS_before_after_addresses\u001b[0;34m(time_UTC, listing)\u001b[0m\n\u001b[1;32m    155\u001b[0m     \u001b[38;5;28;01mraise\u001b[39;00m \u001b[38;5;167;01mValueError\u001b[39;00m(\u001b[38;5;124mf\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mzero-length GFS listing at time \u001b[39m\u001b[38;5;132;01m{\u001b[39;00mtime_UTC\u001b[38;5;132;01m}\u001b[39;00m\u001b[38;5;124m UTC\u001b[39m\u001b[38;5;124m\"\u001b[39m)\n\u001b[1;32m    157\u001b[0m \u001b[38;5;66;03m# min_time = min(listing.forecast_time_UTC)\u001b[39;00m\n\u001b[1;32m    158\u001b[0m \u001b[38;5;66;03m# max_time = max(listing.forecast_time_UTC)\u001b[39;00m\n\u001b[1;32m    159\u001b[0m \n\u001b[1;32m    160\u001b[0m \u001b[38;5;66;03m# logger.info(f\"selecting GFS files for time {time_UTC} UTC between {min_time} UTC and {max_time} UTC\")\u001b[39;00m\n\u001b[1;32m    161\u001b[0m \n\u001b[1;32m    162\u001b[0m \u001b[38;5;66;03m# before = listing[listing.forecast_time_UTC <= time_UTC].iloc[[-1]]\u001b[39;00m\n\u001b[0;32m--> 164\u001b[0m before \u001b[38;5;241m=\u001b[39m \u001b[43mlisting\u001b[49m\u001b[43m[\u001b[49m\u001b[43mlisting\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mforecast_time_UTC\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mapply\u001b[49m\u001b[43m(\u001b[49m\u001b[38;5;28;43;01mlambda\u001b[39;49;00m\u001b[43m \u001b[49m\u001b[43mforecast_time_UTC\u001b[49m\u001b[43m:\u001b[49m\u001b[43m \u001b[49m\u001b[38;5;28;43mstr\u001b[39;49m\u001b[43m(\u001b[49m\u001b[43mforecast_time_UTC\u001b[49m\u001b[43m)\u001b[49m\u001b[43m \u001b[49m\u001b[38;5;241;43m<\u001b[39;49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43m \u001b[49m\u001b[38;5;28;43mstr\u001b[39;49m\u001b[43m(\u001b[49m\u001b[43mtime_UTC\u001b[49m\u001b[43m)\u001b[49m\u001b[43m)\u001b[49m\u001b[43m]\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43miloc\u001b[49m\u001b[43m[\u001b[49m\u001b[43m[\u001b[49m\u001b[38;5;241;43m-\u001b[39;49m\u001b[38;5;241;43m1\u001b[39;49m\u001b[43m]\u001b[49m\u001b[43m]\u001b[49m\n\u001b[1;32m    165\u001b[0m after \u001b[38;5;241m=\u001b[39m listing[listing\u001b[38;5;241m.\u001b[39mforecast_time_UTC\u001b[38;5;241m.\u001b[39mapply(\u001b[38;5;28;01mlambda\u001b[39;00m forecast_time_UTC: \u001b[38;5;28mstr\u001b[39m(forecast_time_UTC) \u001b[38;5;241m>\u001b[39m \u001b[38;5;28mstr\u001b[39m(time_UTC))]\u001b[38;5;241m.\u001b[39miloc[[\u001b[38;5;241m0\u001b[39m]]\n\u001b[1;32m    166\u001b[0m before_after \u001b[38;5;241m=\u001b[39m pd\u001b[38;5;241m.\u001b[39mconcat([before, after])\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/indexing.py:1191\u001b[0m, in \u001b[0;36m_LocationIndexer.__getitem__\u001b[0;34m(self, key)\u001b[0m\n\u001b[1;32m   1189\u001b[0m maybe_callable \u001b[38;5;241m=\u001b[39m com\u001b[38;5;241m.\u001b[39mapply_if_callable(key, \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39mobj)\n\u001b[1;32m   1190\u001b[0m maybe_callable \u001b[38;5;241m=\u001b[39m \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39m_check_deprecated_callable_usage(key, maybe_callable)\n\u001b[0;32m-> 1191\u001b[0m \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43m_getitem_axis\u001b[49m\u001b[43m(\u001b[49m\u001b[43mmaybe_callable\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43maxis\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43maxis\u001b[49m\u001b[43m)\u001b[49m\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/indexing.py:1743\u001b[0m, in \u001b[0;36m_iLocIndexer._getitem_axis\u001b[0;34m(self, key, axis)\u001b[0m\n\u001b[1;32m   1741\u001b[0m \u001b[38;5;66;03m# a list of integers\u001b[39;00m\n\u001b[1;32m   1742\u001b[0m \u001b[38;5;28;01melif\u001b[39;00m is_list_like_indexer(key):\n\u001b[0;32m-> 1743\u001b[0m     \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43m_get_list_axis\u001b[49m\u001b[43m(\u001b[49m\u001b[43mkey\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43maxis\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43maxis\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m   1745\u001b[0m \u001b[38;5;66;03m# a single integer\u001b[39;00m\n\u001b[1;32m   1746\u001b[0m \u001b[38;5;28;01melse\u001b[39;00m:\n\u001b[1;32m   1747\u001b[0m     key \u001b[38;5;241m=\u001b[39m item_from_zerodim(key)\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/indexing.py:1717\u001b[0m, in \u001b[0;36m_iLocIndexer._get_list_axis\u001b[0;34m(self, key, axis)\u001b[0m\n\u001b[1;32m   1714\u001b[0m     \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39mobj\u001b[38;5;241m.\u001b[39m_take_with_is_copy(key, axis\u001b[38;5;241m=\u001b[39maxis)\n\u001b[1;32m   1715\u001b[0m \u001b[38;5;28;01mexcept\u001b[39;00m \u001b[38;5;167;01mIndexError\u001b[39;00m \u001b[38;5;28;01mas\u001b[39;00m err:\n\u001b[1;32m   1716\u001b[0m     \u001b[38;5;66;03m# re-raise with different error message, e.g. test_getitem_ndarray_3d\u001b[39;00m\n\u001b[0;32m-> 1717\u001b[0m     \u001b[38;5;28;01mraise\u001b[39;00m \u001b[38;5;167;01mIndexError\u001b[39;00m(\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mpositional indexers are out-of-bounds\u001b[39m\u001b[38;5;124m\"\u001b[39m) \u001b[38;5;28;01mfrom\u001b[39;00m\u001b[38;5;250m \u001b[39m\u001b[38;5;21;01merr\u001b[39;00m\n",
-      "\u001b[0;31mIndexError\u001b[0m: positional indexers are out-of-bounds"
-     ]
+     "data": {
+      "text/plain": [
+       "Timestamp('2025-05-28 00:00:00')"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
     }
    ],
    "source": [
-    "Ta_C = forecast_Ta_C(\n",
-    "    time_UTC=time_UTC,\n",
-    "    geometry=geometry,\n",
-    ")\n",
+    "from global_forecasting_system import earliest_time_UTC\n",
     "\n",
-    "Ta_C"
+    "earliest = earliest_time_UTC()\n",
+    "earliest"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
-   "id": "31e6c9fc",
+   "execution_count": 9,
+   "id": "4f2aec61",
    "metadata": {},
    "outputs": [
     {
      "data": {
-      "text/html": [
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-       "\n",
-       "    .dataframe thead th {\n",
-       "        text-align: right;\n",
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-       "</style>\n",
-       "<table border=\"1\" class=\"dataframe\">\n",
-       "  <thead>\n",
-       "    <tr style=\"text-align: right;\">\n",
-       "      <th></th>\n",
-       "      <th>forecast_time_UTC</th>\n",
-       "      <th>address</th>\n",
-       "    </tr>\n",
-       "  </thead>\n",
-       "  <tbody>\n",
-       "    <tr>\n",
-       "      <th>0</th>\n",
-       "      <td>2025-05-28 00:00:00</td>\n",
-       "      <td>https://www.ncei.noaa.gov/data/global-forecast...</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>1</th>\n",
-       "      <td>2025-05-28 03:00:00</td>\n",
-       "      <td>https://www.ncei.noaa.gov/data/global-forecast...</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>129</th>\n",
-       "      <td>2025-05-28 06:00:00</td>\n",
-       "      <td>https://www.ncei.noaa.gov/data/global-forecast...</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>130</th>\n",
-       "      <td>2025-05-28 09:00:00</td>\n",
-       "      <td>https://www.ncei.noaa.gov/data/global-forecast...</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>131</th>\n",
-       "      <td>2025-05-28 12:00:00</td>\n",
-       "      <td>https://www.ncei.noaa.gov/data/global-forecast...</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>...</th>\n",
-       "      <td>...</td>\n",
-       "      <td>...</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>253</th>\n",
-       "      <td>2025-06-12 18:00:00</td>\n",
-       "      <td>https://www.ncei.noaa.gov/data/global-forecast...</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>254</th>\n",
-       "      <td>2025-06-12 21:00:00</td>\n",
-       "      <td>https://www.ncei.noaa.gov/data/global-forecast...</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>255</th>\n",
-       "      <td>2025-06-13 00:00:00</td>\n",
-       "      <td>https://www.ncei.noaa.gov/data/global-forecast...</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>256</th>\n",
-       "      <td>2025-06-13 03:00:00</td>\n",
-       "      <td>https://www.ncei.noaa.gov/data/global-forecast...</td>\n",
-       "    </tr>\n",
-       "    <tr>\n",
-       "      <th>257</th>\n",
-       "      <td>2025-06-13 06:00:00</td>\n",
-       "      <td>https://www.ncei.noaa.gov/data/global-forecast...</td>\n",
-       "    </tr>\n",
-       "  </tbody>\n",
-       "</table>\n",
-       "<p>131 rows × 2 columns</p>\n",
-       "</div>"
-      ],
       "text/plain": [
-       "      forecast_time_UTC                                            address\n",
-       "0   2025-05-28 00:00:00  https://www.ncei.noaa.gov/data/global-forecast...\n",
-       "1   2025-05-28 03:00:00  https://www.ncei.noaa.gov/data/global-forecast...\n",
-       "129 2025-05-28 06:00:00  https://www.ncei.noaa.gov/data/global-forecast...\n",
-       "130 2025-05-28 09:00:00  https://www.ncei.noaa.gov/data/global-forecast...\n",
-       "131 2025-05-28 12:00:00  https://www.ncei.noaa.gov/data/global-forecast...\n",
-       "..                  ...                                                ...\n",
-       "253 2025-06-12 18:00:00  https://www.ncei.noaa.gov/data/global-forecast...\n",
-       "254 2025-06-12 21:00:00  https://www.ncei.noaa.gov/data/global-forecast...\n",
-       "255 2025-06-13 00:00:00  https://www.ncei.noaa.gov/data/global-forecast...\n",
-       "256 2025-06-13 03:00:00  https://www.ncei.noaa.gov/data/global-forecast...\n",
-       "257 2025-06-13 06:00:00  https://www.ncei.noaa.gov/data/global-forecast...\n",
-       "\n",
-       "[131 rows x 2 columns]"
+       "datetime.date(2025, 5, 28)"
       ]
      },
-     "execution_count": 5,
+     "execution_count": 9,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "listing = global_forecasting_system.get_GFS_listing()\n",
-    "listing"
+    "earliest.to_pydatetime().date()"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 10,
-   "id": "99726c21",
+   "execution_count": 7,
+   "id": "229d091f",
    "metadata": {},
    "outputs": [
     {
      "data": {
-      "text/html": [
-       "<div>\n",
-       "<style scoped>\n",
-       "    .dataframe tbody tr th:only-of-type {\n",
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-       "\n",
-       "    .dataframe tbody tr th {\n",
-       "        vertical-align: top;\n",
-       "    }\n",
-       "\n",
-       "    .dataframe thead th {\n",
-       "        text-align: right;\n",
-       "    }\n",
-       "</style>\n",
-       "<table border=\"1\" class=\"dataframe\">\n",
-       "  <thead>\n",
-       "    <tr style=\"text-align: right;\">\n",
-       "      <th></th>\n",
-       "      <th>forecast_time_UTC</th>\n",
-       "      <th>address</th>\n",
-       "    </tr>\n",
-       "  </thead>\n",
-       "  <tbody>\n",
-       "  </tbody>\n",
-       "</table>\n",
-       "</div>"
-      ],
       "text/plain": [
-       "Empty DataFrame\n",
-       "Columns: [forecast_time_UTC, address]\n",
-       "Index: []"
+       "pandas._libs.tslibs.timestamps.Timestamp"
       ]
      },
-     "execution_count": 10,
+     "execution_count": 7,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "listing[listing.forecast_time_UTC.apply(lambda forecast_time_UTC: str(forecast_time_UTC) <= str(time_UTC))]"
+    "type(earliest)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
-   "id": "d9e02cc4",
+   "execution_count": 4,
+   "id": "3dd386bd",
    "metadata": {},
    "outputs": [
     {
-     "ename": "IndexError",
-     "evalue": "positional indexers are out-of-bounds",
+     "ename": "ValueError",
+     "evalue": "no GFS files found before time 2025-05-22 21:11:22.358885 UTC",
      "output_type": "error",
      "traceback": [
       "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mIndexError\u001b[0m                                Traceback (most recent call last)",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/indexing.py:1714\u001b[0m, in \u001b[0;36m_iLocIndexer._get_list_axis\u001b[0;34m(self, key, axis)\u001b[0m\n\u001b[1;32m   1713\u001b[0m \u001b[38;5;28;01mtry\u001b[39;00m:\n\u001b[0;32m-> 1714\u001b[0m     \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mobj\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43m_take_with_is_copy\u001b[49m\u001b[43m(\u001b[49m\u001b[43mkey\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43maxis\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43maxis\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m   1715\u001b[0m \u001b[38;5;28;01mexcept\u001b[39;00m \u001b[38;5;167;01mIndexError\u001b[39;00m \u001b[38;5;28;01mas\u001b[39;00m err:\n\u001b[1;32m   1716\u001b[0m     \u001b[38;5;66;03m# re-raise with different error message, e.g. test_getitem_ndarray_3d\u001b[39;00m\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/generic.py:4153\u001b[0m, in \u001b[0;36mNDFrame._take_with_is_copy\u001b[0;34m(self, indices, axis)\u001b[0m\n\u001b[1;32m   4144\u001b[0m \u001b[38;5;250m\u001b[39m\u001b[38;5;124;03m\"\"\"\u001b[39;00m\n\u001b[1;32m   4145\u001b[0m \u001b[38;5;124;03mInternal version of the `take` method that sets the `_is_copy`\u001b[39;00m\n\u001b[1;32m   4146\u001b[0m \u001b[38;5;124;03mattribute to keep track of the parent dataframe (using in indexing\u001b[39;00m\n\u001b[0;32m   (...)\u001b[0m\n\u001b[1;32m   4151\u001b[0m \u001b[38;5;124;03mSee the docstring of `take` for full explanation of the parameters.\u001b[39;00m\n\u001b[1;32m   4152\u001b[0m \u001b[38;5;124;03m\"\"\"\u001b[39;00m\n\u001b[0;32m-> 4153\u001b[0m result \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mtake\u001b[49m\u001b[43m(\u001b[49m\u001b[43mindices\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mindices\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43maxis\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43maxis\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m   4154\u001b[0m \u001b[38;5;66;03m# Maybe set copy if we didn't actually change the index.\u001b[39;00m\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/generic.py:4133\u001b[0m, in \u001b[0;36mNDFrame.take\u001b[0;34m(self, indices, axis, **kwargs)\u001b[0m\n\u001b[1;32m   4129\u001b[0m     indices \u001b[38;5;241m=\u001b[39m np\u001b[38;5;241m.\u001b[39marange(\n\u001b[1;32m   4130\u001b[0m         indices\u001b[38;5;241m.\u001b[39mstart, indices\u001b[38;5;241m.\u001b[39mstop, indices\u001b[38;5;241m.\u001b[39mstep, dtype\u001b[38;5;241m=\u001b[39mnp\u001b[38;5;241m.\u001b[39mintp\n\u001b[1;32m   4131\u001b[0m     )\n\u001b[0;32m-> 4133\u001b[0m new_data \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43m_mgr\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mtake\u001b[49m\u001b[43m(\u001b[49m\n\u001b[1;32m   4134\u001b[0m \u001b[43m    \u001b[49m\u001b[43mindices\u001b[49m\u001b[43m,\u001b[49m\n\u001b[1;32m   4135\u001b[0m \u001b[43m    \u001b[49m\u001b[43maxis\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43m_get_block_manager_axis\u001b[49m\u001b[43m(\u001b[49m\u001b[43maxis\u001b[49m\u001b[43m)\u001b[49m\u001b[43m,\u001b[49m\n\u001b[1;32m   4136\u001b[0m \u001b[43m    \u001b[49m\u001b[43mverify\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[38;5;28;43;01mTrue\u001b[39;49;00m\u001b[43m,\u001b[49m\n\u001b[1;32m   4137\u001b[0m \u001b[43m\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m   4138\u001b[0m \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39m_constructor_from_mgr(new_data, axes\u001b[38;5;241m=\u001b[39mnew_data\u001b[38;5;241m.\u001b[39maxes)\u001b[38;5;241m.\u001b[39m__finalize__(\n\u001b[1;32m   4139\u001b[0m     \u001b[38;5;28mself\u001b[39m, method\u001b[38;5;241m=\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mtake\u001b[39m\u001b[38;5;124m\"\u001b[39m\n\u001b[1;32m   4140\u001b[0m )\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/internals/managers.py:891\u001b[0m, in \u001b[0;36mBaseBlockManager.take\u001b[0;34m(self, indexer, axis, verify)\u001b[0m\n\u001b[1;32m    890\u001b[0m n \u001b[38;5;241m=\u001b[39m \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39mshape[axis]\n\u001b[0;32m--> 891\u001b[0m indexer \u001b[38;5;241m=\u001b[39m \u001b[43mmaybe_convert_indices\u001b[49m\u001b[43m(\u001b[49m\u001b[43mindexer\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mn\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mverify\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mverify\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m    893\u001b[0m new_labels \u001b[38;5;241m=\u001b[39m \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39maxes[axis]\u001b[38;5;241m.\u001b[39mtake(indexer)\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/indexers/utils.py:282\u001b[0m, in \u001b[0;36mmaybe_convert_indices\u001b[0;34m(indices, n, verify)\u001b[0m\n\u001b[1;32m    281\u001b[0m     \u001b[38;5;28;01mif\u001b[39;00m mask\u001b[38;5;241m.\u001b[39many():\n\u001b[0;32m--> 282\u001b[0m         \u001b[38;5;28;01mraise\u001b[39;00m \u001b[38;5;167;01mIndexError\u001b[39;00m(\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mindices are out-of-bounds\u001b[39m\u001b[38;5;124m\"\u001b[39m)\n\u001b[1;32m    283\u001b[0m \u001b[38;5;28;01mreturn\u001b[39;00m indices\n",
-      "\u001b[0;31mIndexError\u001b[0m: indices are out-of-bounds",
-      "\nThe above exception was the direct cause of the following exception:\n",
-      "\u001b[0;31mIndexError\u001b[0m                                Traceback (most recent call last)",
-      "Cell \u001b[0;32mIn[8], line 1\u001b[0m\n\u001b[0;32m----> 1\u001b[0m before \u001b[38;5;241m=\u001b[39m \u001b[43mlisting\u001b[49m\u001b[43m[\u001b[49m\u001b[43mlisting\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mforecast_time_UTC\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mapply\u001b[49m\u001b[43m(\u001b[49m\u001b[38;5;28;43;01mlambda\u001b[39;49;00m\u001b[43m \u001b[49m\u001b[43mforecast_time_UTC\u001b[49m\u001b[43m:\u001b[49m\u001b[43m \u001b[49m\u001b[38;5;28;43mstr\u001b[39;49m\u001b[43m(\u001b[49m\u001b[43mforecast_time_UTC\u001b[49m\u001b[43m)\u001b[49m\u001b[43m \u001b[49m\u001b[38;5;241;43m<\u001b[39;49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43m \u001b[49m\u001b[38;5;28;43mstr\u001b[39;49m\u001b[43m(\u001b[49m\u001b[43mtime_UTC\u001b[49m\u001b[43m)\u001b[49m\u001b[43m)\u001b[49m\u001b[43m]\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43miloc\u001b[49m\u001b[43m[\u001b[49m\u001b[43m[\u001b[49m\u001b[38;5;241;43m-\u001b[39;49m\u001b[38;5;241;43m1\u001b[39;49m\u001b[43m]\u001b[49m\u001b[43m]\u001b[49m\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/indexing.py:1191\u001b[0m, in \u001b[0;36m_LocationIndexer.__getitem__\u001b[0;34m(self, key)\u001b[0m\n\u001b[1;32m   1189\u001b[0m maybe_callable \u001b[38;5;241m=\u001b[39m com\u001b[38;5;241m.\u001b[39mapply_if_callable(key, \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39mobj)\n\u001b[1;32m   1190\u001b[0m maybe_callable \u001b[38;5;241m=\u001b[39m \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39m_check_deprecated_callable_usage(key, maybe_callable)\n\u001b[0;32m-> 1191\u001b[0m \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43m_getitem_axis\u001b[49m\u001b[43m(\u001b[49m\u001b[43mmaybe_callable\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43maxis\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43maxis\u001b[49m\u001b[43m)\u001b[49m\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/indexing.py:1743\u001b[0m, in \u001b[0;36m_iLocIndexer._getitem_axis\u001b[0;34m(self, key, axis)\u001b[0m\n\u001b[1;32m   1741\u001b[0m \u001b[38;5;66;03m# a list of integers\u001b[39;00m\n\u001b[1;32m   1742\u001b[0m \u001b[38;5;28;01melif\u001b[39;00m is_list_like_indexer(key):\n\u001b[0;32m-> 1743\u001b[0m     \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[38;5;28;43mself\u001b[39;49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43m_get_list_axis\u001b[49m\u001b[43m(\u001b[49m\u001b[43mkey\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43maxis\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43maxis\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m   1745\u001b[0m \u001b[38;5;66;03m# a single integer\u001b[39;00m\n\u001b[1;32m   1746\u001b[0m \u001b[38;5;28;01melse\u001b[39;00m:\n\u001b[1;32m   1747\u001b[0m     key \u001b[38;5;241m=\u001b[39m item_from_zerodim(key)\n",
-      "File \u001b[0;32m/opt/homebrew/Caskroom/miniforge/base/envs/global-forecasting-system/lib/python3.10/site-packages/pandas/core/indexing.py:1717\u001b[0m, in \u001b[0;36m_iLocIndexer._get_list_axis\u001b[0;34m(self, key, axis)\u001b[0m\n\u001b[1;32m   1714\u001b[0m     \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[38;5;28mself\u001b[39m\u001b[38;5;241m.\u001b[39mobj\u001b[38;5;241m.\u001b[39m_take_with_is_copy(key, axis\u001b[38;5;241m=\u001b[39maxis)\n\u001b[1;32m   1715\u001b[0m \u001b[38;5;28;01mexcept\u001b[39;00m \u001b[38;5;167;01mIndexError\u001b[39;00m \u001b[38;5;28;01mas\u001b[39;00m err:\n\u001b[1;32m   1716\u001b[0m     \u001b[38;5;66;03m# re-raise with different error message, e.g. test_getitem_ndarray_3d\u001b[39;00m\n\u001b[0;32m-> 1717\u001b[0m     \u001b[38;5;28;01mraise\u001b[39;00m \u001b[38;5;167;01mIndexError\u001b[39;00m(\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mpositional indexers are out-of-bounds\u001b[39m\u001b[38;5;124m\"\u001b[39m) \u001b[38;5;28;01mfrom\u001b[39;00m\u001b[38;5;250m \u001b[39m\u001b[38;5;21;01merr\u001b[39;00m\n",
-      "\u001b[0;31mIndexError\u001b[0m: positional indexers are out-of-bounds"
+      "\u001b[0;31mValueError\u001b[0m                                Traceback (most recent call last)",
+      "Cell \u001b[0;32mIn[4], line 1\u001b[0m\n\u001b[0;32m----> 1\u001b[0m Ta_C \u001b[38;5;241m=\u001b[39m \u001b[43mforecast_Ta_C\u001b[49m\u001b[43m(\u001b[49m\n\u001b[1;32m      2\u001b[0m \u001b[43m    \u001b[49m\u001b[43mtime_UTC\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mtime_UTC\u001b[49m\u001b[43m,\u001b[49m\n\u001b[1;32m      3\u001b[0m \u001b[43m    \u001b[49m\u001b[43mgeometry\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mgeometry\u001b[49m\u001b[43m,\u001b[49m\n\u001b[1;32m      4\u001b[0m \u001b[43m)\u001b[49m\n\u001b[1;32m      6\u001b[0m Ta_C\n",
+      "File \u001b[0;32m~/Projects/global-forecasting-system/global_forecasting_system/global_forecasting_system.py:297\u001b[0m, in \u001b[0;36mforecast_Ta_C\u001b[0;34m(time_UTC, geometry, resampling, directory, listing)\u001b[0m\n\u001b[1;32m    291\u001b[0m \u001b[38;5;28;01mdef\u001b[39;00m\u001b[38;5;250m \u001b[39m\u001b[38;5;21mforecast_Ta_C\u001b[39m(\n\u001b[1;32m    292\u001b[0m         time_UTC: datetime,\n\u001b[1;32m    293\u001b[0m         geometry: rt\u001b[38;5;241m.\u001b[39mRasterGeometry \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m,\n\u001b[1;32m    294\u001b[0m         resampling: \u001b[38;5;28mstr\u001b[39m \u001b[38;5;241m=\u001b[39m \u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mcubic\u001b[39m\u001b[38;5;124m\"\u001b[39m,\n\u001b[1;32m    295\u001b[0m         directory: \u001b[38;5;28mstr\u001b[39m \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m,\n\u001b[1;32m    296\u001b[0m         listing: pd\u001b[38;5;241m.\u001b[39mDataFrame \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m) \u001b[38;5;241m-\u001b[39m\u001b[38;5;241m>\u001b[39m rt\u001b[38;5;241m.\u001b[39mRaster:\n\u001b[0;32m--> 297\u001b[0m     \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[43mforecast_Ta_K\u001b[49m\u001b[43m(\u001b[49m\u001b[43mtime_UTC\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mtime_UTC\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mgeometry\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mgeometry\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mresampling\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mresampling\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mdirectory\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mdirectory\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mlisting\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mlisting\u001b[49m\u001b[43m)\u001b[49m \u001b[38;5;241m-\u001b[39m \u001b[38;5;241m273.15\u001b[39m\n",
+      "File \u001b[0;32m~/Projects/global-forecasting-system/global_forecasting_system/global_forecasting_system.py:289\u001b[0m, in \u001b[0;36mforecast_Ta_K\u001b[0;34m(time_UTC, geometry, resampling, directory, listing)\u001b[0m\n\u001b[1;32m    283\u001b[0m \u001b[38;5;28;01mdef\u001b[39;00m\u001b[38;5;250m \u001b[39m\u001b[38;5;21mforecast_Ta_K\u001b[39m(\n\u001b[1;32m    284\u001b[0m         time_UTC: datetime,\n\u001b[1;32m    285\u001b[0m         geometry: rt\u001b[38;5;241m.\u001b[39mRasterGeometry \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m,\n\u001b[1;32m    286\u001b[0m         resampling: \u001b[38;5;28mstr\u001b[39m \u001b[38;5;241m=\u001b[39m \u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mcubic\u001b[39m\u001b[38;5;124m\"\u001b[39m,\n\u001b[1;32m    287\u001b[0m         directory: \u001b[38;5;28mstr\u001b[39m \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m,\n\u001b[1;32m    288\u001b[0m         listing: pd\u001b[38;5;241m.\u001b[39mDataFrame \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m) \u001b[38;5;241m-\u001b[39m\u001b[38;5;241m>\u001b[39m rt\u001b[38;5;241m.\u001b[39mRaster:\n\u001b[0;32m--> 289\u001b[0m     \u001b[38;5;28;01mreturn\u001b[39;00m \u001b[43mGFS_interpolate\u001b[49m\u001b[43m(\u001b[49m\u001b[43mmessage\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mGFS_TA_MESSAGE\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mtime_UTC\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mtime_UTC\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mgeometry\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mgeometry\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mresampling\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mresampling\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mdirectory\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mdirectory\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mlisting\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mlisting\u001b[49m\u001b[43m)\u001b[49m\n",
+      "File \u001b[0;32m~/Projects/global-forecasting-system/global_forecasting_system/global_forecasting_system.py:247\u001b[0m, in \u001b[0;36mGFS_interpolate\u001b[0;34m(message, time_UTC, geometry, resampling, directory, listing)\u001b[0m\n\u001b[1;32m    240\u001b[0m \u001b[38;5;28;01mdef\u001b[39;00m\u001b[38;5;250m \u001b[39m\u001b[38;5;21mGFS_interpolate\u001b[39m(\n\u001b[1;32m    241\u001b[0m         message: \u001b[38;5;28mint\u001b[39m,\n\u001b[1;32m    242\u001b[0m         time_UTC: datetime,\n\u001b[0;32m   (...)\u001b[0m\n\u001b[1;32m    245\u001b[0m         directory: \u001b[38;5;28mstr\u001b[39m \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m,\n\u001b[1;32m    246\u001b[0m         listing: pd\u001b[38;5;241m.\u001b[39mDataFrame \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m) \u001b[38;5;241m-\u001b[39m\u001b[38;5;241m>\u001b[39m rt\u001b[38;5;241m.\u001b[39mRaster:\n\u001b[0;32m--> 247\u001b[0m     before_after \u001b[38;5;241m=\u001b[39m \u001b[43mGFS_before_after_addresses\u001b[49m\u001b[43m(\u001b[49m\u001b[43mtime_UTC\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mlisting\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mlisting\u001b[49m\u001b[43m)\u001b[49m\n\u001b[1;32m    249\u001b[0m     before_address \u001b[38;5;241m=\u001b[39m before_after\u001b[38;5;241m.\u001b[39miloc[\u001b[38;5;241m0\u001b[39m]\u001b[38;5;241m.\u001b[39maddress\n\u001b[1;32m    250\u001b[0m     logger\u001b[38;5;241m.\u001b[39minfo(\u001b[38;5;124mf\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mbefore URL: \u001b[39m\u001b[38;5;132;01m{\u001b[39;00mcolored_logging\u001b[38;5;241m.\u001b[39mURL(before_address)\u001b[38;5;132;01m}\u001b[39;00m\u001b[38;5;124m\"\u001b[39m)\n",
+      "File \u001b[0;32m~/Projects/global-forecasting-system/global_forecasting_system/global_forecasting_system.py:177\u001b[0m, in \u001b[0;36mGFS_before_after_addresses\u001b[0;34m(time_UTC, listing)\u001b[0m\n\u001b[1;32m    174\u001b[0m before_rows \u001b[38;5;241m=\u001b[39m listing[listing\u001b[38;5;241m.\u001b[39mforecast_time_UTC\u001b[38;5;241m.\u001b[39mapply(\u001b[38;5;28;01mlambda\u001b[39;00m forecast_time_UTC: \u001b[38;5;28mstr\u001b[39m(forecast_time_UTC) \u001b[38;5;241m<\u001b[39m\u001b[38;5;241m=\u001b[39m \u001b[38;5;28mstr\u001b[39m(time_UTC))]\n\u001b[1;32m    176\u001b[0m \u001b[38;5;28;01mif\u001b[39;00m \u001b[38;5;28mlen\u001b[39m(before_rows) \u001b[38;5;241m==\u001b[39m \u001b[38;5;241m0\u001b[39m:\n\u001b[0;32m--> 177\u001b[0m     \u001b[38;5;28;01mraise\u001b[39;00m \u001b[38;5;167;01mValueError\u001b[39;00m(\u001b[38;5;124mf\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mno GFS files found before time \u001b[39m\u001b[38;5;132;01m{\u001b[39;00mtime_UTC\u001b[38;5;132;01m}\u001b[39;00m\u001b[38;5;124m UTC\u001b[39m\u001b[38;5;124m\"\u001b[39m)\n\u001b[1;32m    179\u001b[0m before \u001b[38;5;241m=\u001b[39m before_rows\u001b[38;5;241m.\u001b[39miloc[[\u001b[38;5;241m-\u001b[39m\u001b[38;5;241m1\u001b[39m]]\n\u001b[1;32m    181\u001b[0m after_rows \u001b[38;5;241m=\u001b[39m listing[listing\u001b[38;5;241m.\u001b[39mforecast_time_UTC\u001b[38;5;241m.\u001b[39mapply(\u001b[38;5;28;01mlambda\u001b[39;00m forecast_time_UTC: \u001b[38;5;28mstr\u001b[39m(forecast_time_UTC) \u001b[38;5;241m>\u001b[39m \u001b[38;5;28mstr\u001b[39m(time_UTC))]\n",
+      "\u001b[0;31mValueError\u001b[0m: no GFS files found before time 2025-05-22 21:11:22.358885 UTC"
      ]
     }
    ],
+   "source": [
+    "Ta_C = forecast_Ta_C(\n",
+    "    time_UTC=time_UTC,\n",
+    "    geometry=geometry,\n",
+    ")\n",
+    "\n",
+    "Ta_C"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "31e6c9fc",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "listing = global_forecasting_system.get_GFS_listing()\n",
+    "listing"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "99726c21",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "listing[listing.forecast_time_UTC.apply(lambda forecast_time_UTC: str(forecast_time_UTC) <= str(time_UTC))]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "d9e02cc4",
+   "metadata": {},
+   "outputs": [],
    "source": [
     "before = listing[listing.forecast_time_UTC.apply(lambda forecast_time_UTC: str(forecast_time_UTC) <= str(time_UTC))].iloc[[-1]]"
    ]
@@ -319,6 +195,14 @@
    "metadata": {},
    "outputs": [],
    "source": []
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "8ca59e87",
+   "metadata": {},
+   "outputs": [],
+   "source": []
   }
  ],
  "metadata": {
diff --git a/global_forecasting_system/__init__.py b/global_forecasting_system/__init__.py
index 479d2e5..23ccd71 100644
--- a/global_forecasting_system/__init__.py
+++ b/global_forecasting_system/__init__.py
@@ -1,3 +1,3 @@
 from .global_forecasting_system import *
 
-__version__ = "1.1.1"
+__version__ = "1.2.0"
diff --git a/global_forecasting_system/global_forecasting_system.py b/global_forecasting_system/global_forecasting_system.py
index c85a046..d482da9 100644
--- a/global_forecasting_system/global_forecasting_system.py
+++ b/global_forecasting_system/global_forecasting_system.py
@@ -142,6 +142,20 @@ def get_GFS_listing(date_URL: str = None) -> pd.DataFrame:
     
     return address_df
 
+def earliest_time_UTC(listing: pd.DataFrame = None) -> datetime:
+    if listing is None:
+        listing = get_GFS_listing()
+
+    if len(listing) == 0:
+        raise ValueError("zero-length GFS listing")
+
+    earliest_time = min(listing.forecast_time_UTC).to_pydatetime()
+
+    return earliest_time
+
+def earliest_date_UTC(listing: pd.DataFrame = None) -> date:
+    return earliest_date_UTC(listing=listing).date()
+
 def GFS_before_after_addresses(time_UTC: datetime, listing: pd.DataFrame = None) -> pd.DataFrame:
     if not isinstance(time_UTC, datetime):
         time_UTC = parser.parse(time_UTC)
diff --git a/pyproject.toml b/pyproject.toml
index ee3819d..d209c86 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "global-forecasting-system"
-version = "1.1.1"
+version = "1.2.0"
 description = "Global Forecasting System (GFS) Search & Download Utility"
 readme = "README.md"
 authors = [