Daylight Savings Time has changed up some time zones so that they're another hour behind now (for example, GMT-7 turns into GMT-8). Unfortunately, this does complicate the 24-hour cooldown rule a little, since the LOs are in a part of the world that does Daylight Savings, while some League players might not.
If you're slightly unsure of how Daylight Savings Time affects your League matches, try to leave a little bit more of a gap (say 26 hours or so) in between your matches that were played yesterday and matches that you'll play today, so that the changing timezones don't cause problems with the cooldowns. Starting tomorrow, the cooldown clocks should work as normal.