The change occurs one second after 23:59:59 on Thursday to become 1:00:00 on the last Friday in April shortening the day to 23 hours. Summer time ends one second after 23:59:59 to become 23:00:00 on the last Thursday of September lengthening the day to 25 hours. The date does not change one second after the first 23:59:59 occurred; for all practical purposes, midnight does not occur until after the second 23:59:59.