Time Zones

Fixed time zones in calculations where it matters -- left untouched areas where we were simply comparing the time between two dates.

Author: Seth Battis

config.inc.php

@@ -8,6 +8,8 @@
 	define('TOOL_START_PAGE', 'index.php');
 }
 
+define('SCHOOL_TIME_ZONE', 'America/New_York'); // Go Sox! Stupid PHP.
+
 define('DATA_COLLECTION_CRONTAB', '0 0 * * *'); // collect data every night at midnight
 
 /* graph coloring (tied into CSS styling of summary text, so be sure to use

private/data-collection.php

@@ -121,13 +121,18 @@ function collectStatistics($term) {
 
 								// check for due dates
 								$dueDate = new DateTime($assignment['due_at']);
+								$dueDate->setTimeZone(new DateTimeZone(SCHOOL_TIME_ZONE));
 								if (($timestamp - $dueDate->getTimestamp()) > 0) {
 									$statistic['assignments_due_count']++;
 
 									// update created_modified_histogram
-									$createdModifiedHistogram[HISTOGRAM_CREATED][date("g:00 a", strtotime($assignment['created_at']))]++;
-									if ($assignment['updated_at'] != $assignment['created_at']) {
-										$createdModifiedHistogram[HISTOGRAM_MODIFIED][date("g:00 a", strtotime($assignment['updated_at']))]++;
+									$createdAt = new DateTime($assignment['created_at']);
+									$createdAt->setTimeZone(new DateTimeZone(SCHOOL_TIME_ZONE));
+									$updatedAt = new DateTime($assignment['updated_at']);
+									$updatedAt->setTimeZone(new DateTimeZone(SCHOOL_TIME_ZONE));
+									$createdModifiedHistogram[HISTOGRAM_CREATED][$createdAt->format('g:00 a')]++;
+									if ($createdAt != $updatedAt) {
+										$createdModifiedHistogram[HISTOGRAM_MODIFIED][$updatedAt->format('g:00 a')]++;
 									}
 
 									// tally lead time on the assignment