backup_cron_helper_testcase::test_next_automated_backup failing twice a year

1) backup_cron_helper_testcase::test_next_automated_backup
Failed asserting that two strings are equal.
— Expected
+++ Actual
@@ @@
-'0-08:00'
+'0-07:00'

/var/lib/jenkins/moodle/behat_whole_suite_m/backup/util/helper/tests/cronhelper_test.php:295
/var/lib/jenkins/moodle/behat_whole_suite_m/lib/phpunit/classes/advanced_testcase.php:80

To re-run:
vendor/bin/phpunit backup_cron_helper_testcase backup/util/helper/tests/cronhelper_test.php