From 3b6acb99bddc6a45e2b83e5c41447c48795cf40c Mon Sep 17 00:00:00 2001
From: Simey Lameze <simey@moodle.com>
Date: Mon, 4 Sep 2023 12:16:29 +0800
Subject: [PATCH] MDL-75928 format_week: improve get_section_dates one week
 calc

---
 course/format/weeks/lib.php                   | 23 ++++++++++++++-----
 .../format/weeks/tests/format_weeks_test.php  |  4 ++--
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/course/format/weeks/lib.php b/course/format/weeks/lib.php
index 3bd726b4fc35a..79b0b119fb41b 100644
--- a/course/format/weeks/lib.php
+++ b/course/format/weeks/lib.php
@@ -406,14 +406,25 @@ public function get_section_dates($section, $startdate = false) {
         } else {
             $sectionnum = $section;
         }
-        $oneweekseconds = 604800;
-        // Hack alert. We add 2 hours to avoid possible DST problems. (e.g. we go into daylight
-        // savings and the date changes.
-        $startdate = $startdate + 7200;
+
+        // Create a DateTime object for the start date.
+        $startdateobj = new DateTime("@$startdate");
+
+        // Calculate the interval for one week.
+        $oneweekinterval = new DateInterval('P7D');
+
+        // Calculate the interval for the specified number of sections.
+        for ($i = 1; $i < $sectionnum; $i++) {
+            $startdateobj->add($oneweekinterval);
+        }
+
+        // Calculate the end date.
+        $enddateobj = clone $startdateobj;
+        $enddateobj->add($oneweekinterval);
 
         $dates = new stdClass();
-        $dates->start = $startdate + ($oneweekseconds * ($sectionnum - 1));
-        $dates->end = $dates->start + $oneweekseconds;
+        $dates->start = $startdateobj->getTimestamp();
+        $dates->end = $enddateobj->getTimestamp();
 
         return $dates;
     }
diff --git a/course/format/weeks/tests/format_weeks_test.php b/course/format/weeks/tests/format_weeks_test.php
index dd5eb990a366c..8d6414a2a0c53 100644
--- a/course/format/weeks/tests/format_weeks_test.php
+++ b/course/format/weeks/tests/format_weeks_test.php
@@ -219,8 +219,8 @@ public function test_default_course_enddate() {
         $courseform = new \testable_course_edit_form(null, $args);
         $courseform->definition_after_data();
 
-        // format_weeks::get_section_dates is adding 2h to avoid DST problems, we need to replicate it here.
-        $enddate = $params['startdate'] + (WEEKSECS * $params['numsections']) + 7200;
+        // Calculate the expected end date.
+        $enddate = $params['startdate'] + (WEEKSECS * $params['numsections']);
 
         $weeksformat = course_get_format($course->id);
         $this->assertEquals($enddate, $weeksformat->get_default_course_enddate($courseform->get_quick_form()));