diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 668c07bd4c..ad0c66919a 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -20,10 +20,9 @@ jobs:
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
-    - name: Set up Python 3.8
-      uses: actions/setup-python@v4
+    - uses: actions/setup-python@v4
       with:
-        python-version: 3.8
+        python-version: 3.11
 
     - name: Install dependencies
       run: |
diff --git a/.github/workflows/doctests.yaml b/.github/workflows/doctests.yaml
index d29af1cf29..afe2580a27 100644
--- a/.github/workflows/doctests.yaml
+++ b/.github/workflows/doctests.yaml
@@ -8,15 +8,14 @@ jobs:
       max-parallel: 4
       fail-fast: false
       matrix:
-        python-version: ['3.9']
+        python-version: ['3.11']
         platform: [ubuntu-latest]
 
     runs-on: ${{ matrix.platform }}
 
     steps:
     - uses: actions/checkout@v3
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+    - uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install other dependencies
diff --git a/.github/workflows/lints.yml b/.github/workflows/lints.yml
index 0931abe329..9a8ac1effd 100644
--- a/.github/workflows/lints.yml
+++ b/.github/workflows/lints.yml
@@ -12,6 +12,8 @@ jobs:
     steps:
     - uses: actions/checkout@v3
     - uses: actions/setup-python@v4
+      with:
+          python-version: '3.11'
     - name: Install tools
       run: pip install "ruff==0.2.2" "docformatter[tomli]==1.5.0"
     - name: Ruff (Flake8)
diff --git a/.github/workflows/mxnet_nightly.yml b/.github/workflows/mxnet_nightly.yml
deleted file mode 100644
index 75f29f4f29..0000000000
--- a/.github/workflows/mxnet_nightly.yml
+++ /dev/null
@@ -1,39 +0,0 @@
-name: MXNet nightly
-
-on:
-  schedule:
-    - cron:  '0 0 * * *'
-
-jobs:
-  test-mxnet-nightly:
-
-    strategy:
-      max-parallel: 4
-      fail-fast: false
-      matrix:
-        python-version: ['3.8']
-        platform: [ubuntu-latest, windows-latest]
-
-    runs-on: ${{ matrix.platform }}
-
-    steps:
-    - uses: actions/checkout@v3
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
-      with:
-        python-version: ${{ matrix.python-version }}
-    - name: Install dependencies
-      run: |
-        pip install pip==20.2
-        pip install --pre "mxnet<2" -f https://dist.mxnet.io/python
-        pip install "torch==1.10.0" "pytorch-lightning~=1.5" -f https://download.pytorch.org/whl/cpu/torch_stable.html
-        pip install -e ".[shell]" \
-          -r requirements/requirements-test.txt \
-          -r requirements/requirements-extras-sagemaker-sdk.txt \
-          -r requirements/requirements-extras-m-competitions.txt \
-          -r requirements/requirements-rotbaum.txt \
-          -r requirements/requirements-extras-anomaly-evaluation.txt \
-          -r requirements/requirements-extras-autogluon.txt
-    - name: Test with pytest
-      run: |
-        pytest -m 'not (gpu or serial)' --cov=gluonts --cov-report=term --cov-report xml test
diff --git a/.github/workflows/pypi.yml b/.github/workflows/pypi.yml
index d2ca008f29..25ff90fe1c 100644
--- a/.github/workflows/pypi.yml
+++ b/.github/workflows/pypi.yml
@@ -12,10 +12,9 @@ jobs:
     - uses: actions/checkout@v4
     - name: Get tags
       run: git fetch --tags origin
-    - name: Set up Python 3.8
-      uses: actions/setup-python@v4
+    - uses: actions/setup-python@v4
       with:
-        python-version: '3.8'
+        python-version: '3.11'
     - name: Install dependencies
       run: |
         python -m pip install -U pip
diff --git a/.github/workflows/style_type_checks.yml b/.github/workflows/style_type_checks.yml
index 48c2178edc..271ca39ff0 100644
--- a/.github/workflows/style_type_checks.yml
+++ b/.github/workflows/style_type_checks.yml
@@ -10,6 +10,8 @@ jobs:
     - uses: actions/checkout@v3
     - uses: extractions/setup-just@v1
     - uses: actions/setup-python@v4
+      with:
+          python-version: '3.11'
     - name: Install dependencies
       run: |
         pip install .
diff --git a/.github/workflows/test_release_unix_nightly.yml b/.github/workflows/test_release_unix_nightly.yml
deleted file mode 100644
index f058fafcaa..0000000000
--- a/.github/workflows/test_release_unix_nightly.yml
+++ /dev/null
@@ -1,39 +0,0 @@
-name: Test latest release nightly Ubuntu
-
-on:
-  schedule:
-    - cron:  '0 0 * * *'
-
-jobs:
-  test-stable-ubuntu:
-
-    strategy:
-      max-parallel: 4
-      fail-fast: false
-      matrix:
-        python-version: ['3.8']
-
-    runs-on: ubuntu-latest
-    steps:
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
-      with:
-        python-version: ${{ matrix.python-version }}
-    - name: Clone and install dependencies
-      run: |
-        git clone https://github.com/awslabs/gluonts --branch $(curl https://api.github.com/repos/awslabs/gluonts/releases/latest | grep tag_name | cut -d : -f 2,3 | tr -d \"\ | tr -d \,\ )
-        cd gluon-ts
-        pip install pip==20.2
-        pip install "mxnet~=1.8.0" "torch==1.10.0" "pytorch-lightning~=1.5" \
-          -f https://download.pytorch.org/whl/cpu/torch_stable.html
-        pip install -e ".[shell]" \
-          -r requirements/requirements-test.txt \
-          -r requirements/requirements-extras-sagemaker-sdk.txt \
-          -r requirements/requirements-extras-m-competitions.txt \
-          -r requirements/requirements-rotbaum.txt \
-          -r requirements/requirements-extras-anomaly-evaluation.txt \
-          -r requirements/requirements-extras-autogluon.txt
-    - name: Test with pytest
-      run: |
-        cd gluon-ts
-        pytest -m 'not (gpu or serial)' --cov=gluonts --cov-report=term --cov-report xml test
diff --git a/.github/workflows/test_release_win32_nightly.yml b/.github/workflows/test_release_win32_nightly.yml
deleted file mode 100644
index b9cda3fb92..0000000000
--- a/.github/workflows/test_release_win32_nightly.yml
+++ /dev/null
@@ -1,40 +0,0 @@
-name: Test latest release nightly Windows
-
-on:
-  schedule:
-    - cron:  '0 0 * * *'
-
-jobs:
-  test-stable-windows:
-
-    strategy:
-      max-parallel: 4
-      fail-fast: false
-      matrix:
-        python-version: ['3.8']
-
-    runs-on: windows-latest
-    steps:
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
-      with:
-        python-version: ${{ matrix.python-version }}
-    - name: Clone and install dependencies
-      run: |
-        $tmp=(Invoke-WebRequest -Uri https://api.github.com/repos/awslabs/gluonts/releases/latest).Content | ConvertFrom-Json | Select-Object tag_name
-        $tmp=$tmp.psobject.properties.value.trim() 
-        git clone https://github.com/awslabs/gluonts --branch $tmp
-        cd gluon-ts
-        pip install "mxnet~=1.7.0" torch "pytorch-lightning~=1.5"
-        pip install -e ".[shell]" \
-          -r requirements/requirements-test.txt \
-          -r requirements/requirements-extras-sagemaker-sdk.txt \
-          -r requirements/requirements-extras-m-competitions.txt \
-          -r requirements/requirements-rotbaum.txt \
-          -r requirements/requirements-extras-anomaly-evaluation.txt \
-          -r requirements/requirements-extras-autogluon.txt
-      shell: powershell
-    - name: Test with pytest
-      run: |
-        cd gluon-ts
-        pytest -m 'not (gpu or serial)' --cov=gluonts --cov-report=term --cov-report xml test
diff --git a/.github/workflows/tests-nixtla.yaml b/.github/workflows/tests-nixtla.yaml
index 86aefed138..8c35fd75b6 100644
--- a/.github/workflows/tests-nixtla.yaml
+++ b/.github/workflows/tests-nixtla.yaml
@@ -8,15 +8,14 @@ jobs:
       max-parallel: 4
       fail-fast: false
       matrix:
-        python-version: ['3.8']
+        python-version: ['3.11']
         platform: [ubuntu-latest]
 
     runs-on: ${{ matrix.platform }}
 
     steps:
     - uses: actions/checkout@v3
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+    - uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install other dependencies
diff --git a/.github/workflows/tests-nursery.yml b/.github/workflows/tests-nursery.yml
index 5bca25ec1c..60423bccb9 100644
--- a/.github/workflows/tests-nursery.yml
+++ b/.github/workflows/tests-nursery.yml
@@ -8,7 +8,7 @@ jobs:
       max-parallel: 1
       fail-fast: false
       matrix:
-        python-version: ['3.8']
+        python-version: ['3.11']
         platform: [ubuntu-latest]
 
     runs-on: ${{ matrix.platform }}
@@ -17,8 +17,7 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+    - uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install MXNet (Linux)
diff --git a/.github/workflows/tests-prophet.yaml b/.github/workflows/tests-prophet.yaml
index c1d3bdc586..f5533255f6 100644
--- a/.github/workflows/tests-prophet.yaml
+++ b/.github/workflows/tests-prophet.yaml
@@ -8,15 +8,14 @@ jobs:
       max-parallel: 4
       fail-fast: false
       matrix:
-        python-version: ['3.8']
+        python-version: ['3.11']
         platform: [ubuntu-latest]
 
     runs-on: ${{ matrix.platform }}
 
     steps:
     - uses: actions/checkout@v3
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+    - uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install other dependencies
diff --git a/.github/workflows/tests-r.yml b/.github/workflows/tests-r.yml
index 52c8ab6206..f0df985db2 100644
--- a/.github/workflows/tests-r.yml
+++ b/.github/workflows/tests-r.yml
@@ -8,7 +8,7 @@ jobs:
       max-parallel: 4
       fail-fast: false
       matrix:
-        python-version: ['3.9']
+        python-version: ['3.11']
         platform: [ubuntu-latest]
 
     runs-on: ${{ matrix.platform }}
@@ -32,8 +32,7 @@ jobs:
           libxml2-dev \
           libcurl4-openssl-dev
         Rscript -e 'install.packages(c("forecast", "nnfor", "hts"), repos="https://cloud.r-project.org")'
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+    - uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install Python dependencies
diff --git a/.github/workflows/tests-torch.yml b/.github/workflows/tests-torch.yml
index fde0bf221f..87a1a0b5cd 100644
--- a/.github/workflows/tests-torch.yml
+++ b/.github/workflows/tests-torch.yml
@@ -8,7 +8,7 @@ jobs:
       max-parallel: 4
       fail-fast: false
       matrix:
-        python-version: ['3.8', '3.9', '3.10']
+        python-version: ['3.9', '3.10', '3.11']
         platform: [ubuntu-latest]
 
     runs-on: ${{ matrix.platform }}
@@ -21,10 +21,9 @@ jobs:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
       run: |
-        pip install ".[arrow]" \
+        pip install ".[arrow,torch,shell]" \
           -r requirements/requirements-test.txt \
-          -r requirements/requirements-extras-m-competitions.txt \
-          -r requirements/requirements-pytorch.txt
+          -r requirements/requirements-extras-m-competitions.txt
         pip install --no-deps -r requirements/requirements-extras-cpflows.txt
     - name: Test with pytest
       run: |
diff --git a/.github/workflows/tests-xgboost.yaml b/.github/workflows/tests-xgboost.yaml
index 022b766cf6..fa0dca686c 100644
--- a/.github/workflows/tests-xgboost.yaml
+++ b/.github/workflows/tests-xgboost.yaml
@@ -8,7 +8,7 @@ jobs:
       max-parallel: 4
       fail-fast: false
       matrix:
-        python-version: ['3.8', '3.9', '3.10']
+        python-version: ['3.11']
         platform: [ubuntu-latest]
 
     runs-on: ${{ matrix.platform }}
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 7119f0d83d..e5ba432a34 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -8,15 +8,14 @@ jobs:
       max-parallel: 4
       fail-fast: false
       matrix:
-        python-version: ['3.8', '3.9', '3.10']
+        python-version: ['3.9', '3.10', '3.11']
         platform: [ubuntu-latest]
 
     runs-on: ${{ matrix.platform }}
 
     steps:
     - uses: actions/checkout@v3
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+    - uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install other dependencies
diff --git a/requirements/requirements-docs.txt b/requirements/requirements-docs.txt
index 645e7632c3..382421d85a 100644
--- a/requirements/requirements-docs.txt
+++ b/requirements/requirements-docs.txt
@@ -6,7 +6,7 @@ notedown
 lxml~=5.1.0
 pytest-runner~=2.11
 recommonmark
-sphinx~=4.0
+sphinx~=5.0
 docutils<=0.16
 optuna~=2.10
 furo==2022.6.4.1
diff --git a/requirements/requirements-extras-shell.txt b/requirements/requirements-extras-shell.txt
index 4a740fb6b4..9d71394cd0 100644
--- a/requirements/requirements-extras-shell.txt
+++ b/requirements/requirements-extras-shell.txt
@@ -1,2 +1,2 @@
-flask~=2.0
-waitress~=2.1.2
+flask~=3.0
+waitress~=3.0.1
diff --git a/src/gluonts/dataset/repository/_ercot.py b/src/gluonts/dataset/repository/_ercot.py
index d013a09c9f..7e144d988e 100644
--- a/src/gluonts/dataset/repository/_ercot.py
+++ b/src/gluonts/dataset/repository/_ercot.py
@@ -26,7 +26,7 @@ def generate_ercot_dataset(dataset_path: Path, dataset_writer: DatasetWriter):
     df.ffill(inplace=True)
     regions = [col for col in df.columns if col not in ["ds", "y"]]
 
-    freq = "1H"
+    freq = "1h"
     prediction_length = 24
 
     start = pd.Period(df["ds"][0], freq=freq)
diff --git a/src/gluonts/dataset/repository/_gp_copula_2019.py b/src/gluonts/dataset/repository/_gp_copula_2019.py
index 88c6becea2..41d5da9ba6 100644
--- a/src/gluonts/dataset/repository/_gp_copula_2019.py
+++ b/src/gluonts/dataset/repository/_gp_copula_2019.py
@@ -63,7 +63,7 @@ class GPCopulaDataset(NamedTuple):
         # original dataset can be found at https://archive.ics.uci.edu/ml/datasets/ElectricityLoadDiagrams20112014#
         num_series=370,
         prediction_length=24,
-        freq="H",
+        freq="h",
         rolling_evaluations=7,
         max_target_dim=None,
     ),
@@ -73,7 +73,7 @@ class GPCopulaDataset(NamedTuple):
         # note there are 963 in the original dataset from https://archive.ics.uci.edu/ml/datasets/PEMS-SF
         num_series=963,
         prediction_length=24,
-        freq="H",
+        freq="h",
         rolling_evaluations=7,
         max_target_dim=None,
     ),
@@ -82,7 +82,7 @@ class GPCopulaDataset(NamedTuple):
         url=root + "solar_nips.tar.gz",
         num_series=137,
         prediction_length=24,
-        freq="H",
+        freq="h",
         rolling_evaluations=7,
         max_target_dim=None,
     ),
diff --git a/src/gluonts/dataset/repository/_lstnet.py b/src/gluonts/dataset/repository/_lstnet.py
index e933666c77..0253cffd95 100644
--- a/src/gluonts/dataset/repository/_lstnet.py
+++ b/src/gluonts/dataset/repository/_lstnet.py
@@ -91,7 +91,7 @@ class LstnetDataset(NamedTuple):
         prediction_length=24,
         rolling_evaluations=7,
         start_date="2012-01-01",
-        freq="1H",
+        freq="1h",
         agg_freq=None,
     ),
     "traffic": LstnetDataset(
@@ -105,7 +105,7 @@ class LstnetDataset(NamedTuple):
         prediction_length=24,
         rolling_evaluations=7,
         start_date="2015-01-01",
-        freq="H",
+        freq="h",
         agg_freq=None,
     ),
     "solar-energy": LstnetDataset(
@@ -117,7 +117,7 @@ class LstnetDataset(NamedTuple):
         rolling_evaluations=7,
         start_date="2006-01-01",
         freq="10min",
-        agg_freq="1H",
+        agg_freq="1h",
     ),
 }
 
diff --git a/src/gluonts/dataset/repository/_tsf_datasets.py b/src/gluonts/dataset/repository/_tsf_datasets.py
index ba073cdf4c..b6ff0340b2 100644
--- a/src/gluonts/dataset/repository/_tsf_datasets.py
+++ b/src/gluonts/dataset/repository/_tsf_datasets.py
@@ -278,11 +278,15 @@ def generate_forecasting_dataset(
 def default_prediction_length_from_frequency(freq: str) -> int:
     prediction_length_map = {
         "T": 60,
+        "min": 60,
         "H": 48,
+        "h": 48,
         "D": 30,
         "W-SUN": 8,
         "M": 12,
+        "ME": 12,
         "Y": 4,
+        "YE": 4,
     }
     try:
         freq = to_offset(freq).name
diff --git a/src/gluonts/dataset/repository/_tsf_reader.py b/src/gluonts/dataset/repository/_tsf_reader.py
index 45386864a7..ca87bb27f3 100644
--- a/src/gluonts/dataset/repository/_tsf_reader.py
+++ b/src/gluonts/dataset/repository/_tsf_reader.py
@@ -49,10 +49,10 @@ def frequency_converter(freq: str):
 
 BASE_FREQ_TO_PANDAS_OFFSET: Dict[str, str] = {
     "seconds": "S",
-    "minutely": "T",
-    "minutes": "T",
-    "hourly": "H",
-    "hours": "H",
+    "minutely": "min",
+    "minutes": "min",
+    "hourly": "h",
+    "hours": "h",
     "daily": "D",
     "days": "D",
     "weekly": "W",
diff --git a/src/gluonts/dataset/repository/_uber_tlc.py b/src/gluonts/dataset/repository/_uber_tlc.py
index 73aabd0701..26a086db43 100644
--- a/src/gluonts/dataset/repository/_uber_tlc.py
+++ b/src/gluonts/dataset/repository/_uber_tlc.py
@@ -28,7 +28,7 @@ def generate_uber_dataset(
     prediction_length: int,
     dataset_writer: DatasetWriter,
 ):
-    subsets = {"daily": "1D", "hourly": "1H"}
+    subsets = {"daily": "1D", "hourly": "1h"}
     assert (
         uber_freq.lower() in subsets
     ), f"invalid uber_freq='{uber_freq}'. Allowed values: {subsets.keys()}"
diff --git a/src/gluonts/testutil/shell.py b/src/gluonts/testutil/shell.py
index 5e1815db6f..c723ae6712 100644
--- a/src/gluonts/testutil/shell.py
+++ b/src/gluonts/testutil/shell.py
@@ -21,7 +21,7 @@
 import typing
 import waitress
 from contextlib import closing, contextmanager
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from multiprocessing.context import ForkContext
 from pathlib import Path
 from typing import Any, ContextManager, Dict, Iterable, List, Optional, Type
@@ -119,7 +119,7 @@ def free_port() -> int:
 class Server:
     env: ServeEnv
     forecaster_type: Optional[Type[Predictor]]
-    settings: Settings = Settings()
+    settings: Settings = field(default_factory=Settings)
 
     def run(self):
         flask_app = make_flask_app(
diff --git a/test/conftest.py b/test/conftest.py
index b624259a15..8ec8649909 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -30,7 +30,7 @@
 
 try:
     import mxnet as mx
-except ImportError:
+except (ImportError, OSError):
     mx = None
 
 try:
diff --git a/test/core/test_serde_dataclass.py b/test/core/test_serde_dataclass.py
index 324e33c746..f602699711 100644
--- a/test/core/test_serde_dataclass.py
+++ b/test/core/test_serde_dataclass.py
@@ -20,14 +20,13 @@
 @serde.dataclass
 class Estimator:
     prediction_length: int
-    context_length: int = serde.OrElse(
-        lambda prediction_length: prediction_length * 2
-    )
+    context_length: int = serde.EVENTUAL
 
     use_feat_static_cat: bool = True
     cardinality: List[int] = serde.EVENTUAL
 
-    def __eventually__(self, cardinality):
+    def __eventually__(self, context_length, cardinality):
+        context_length.set_default(self.prediction_length * 2)
         if not self.use_feat_static_cat:
             cardinality.set([1])
         else:
diff --git a/test/dataset/test_tsf_reader.py b/test/dataset/test_tsf_reader.py
index 2261d7ebfc..686b3f4d2c 100644
--- a/test/dataset/test_tsf_reader.py
+++ b/test/dataset/test_tsf_reader.py
@@ -20,10 +20,10 @@
     "input_freq_str, output_freq_str",
     [
         ("30_seconds", "30S"),
-        ("minutely", "T"),
-        ("10_minutes", "10T"),
-        ("hourly", "H"),
-        ("half_hourly", "0.5H"),
+        ("minutely", "min"),
+        ("10_minutes", "10min"),
+        ("hourly", "h"),
+        ("half_hourly", "0.5h"),
         ("daily", "D"),
         ("7_days", "7D"),
         ("weekly", "W"),