set the/(one's) clock(s) ahead(redirected from set their clocks ahead)
set the/(one's) clock(s) ahead
To advance the time on one's clock(s) ahead by one hour to account for the beginning of daylight saving time. Don't forget to set your clock ahead tonight or you'll end up oversleeping tomorrow! I hate having to set the clocks ahead every spring, it's such an antiquated custom.