Today I was given the O Tannenbaum hat, but the description says ask, answer, or vote on December 25th, I thought we were using UTC time here?
If so why did I get this today?
It is only the 24th of December UTC, I added the hat (tree?) to my profile picture, so you can see it there.
From : Why are date-based hats awarded too early?
So, the official answer is: we over-awarded the hat so that people in Auckland / Tokyo / Shanghai / Vanuatu wouldn't have to wait until their midday to receive it.
You're all mostly programmers, so you should be reasonably familiar with how much of a headache timezones can be sometimes. Since Stack Exchange is run on UTC, we have to leave a +/- 12 hour buffer so that the nations around the International Date Line have just as much opportunity to grab hats as people along the 0 longitude.
This behavior will also occur for the other hats that are date-sensitive. This included L'Chaim, and will include Tis the Season and the New Year's Eve Hat / Auld Lang Syne.
Basically: Don't panic! It's a feature, not a bug!
Quoting the accepted answer on Why didn't (or did) I or some other user get a hat although the requirements were (or weren't) fulfilled?:
Unless the requirement mentions a specific timezone, hats that are date-based are often awarded for 14 hours before and 12 hours after the specified date in UTC, to accomodate people everywhere in the world. This means you can earn such a hat even though for you it's not even that day yet.
Doing the math:
25 Dec 2015 00:00 AM UTC - 14h = 24 Dec 2015 10:00 AM UTC
25 Dec 2015 00:00 AM UTC + 12h = 25 Dec 2015 12:00 AM UTC
This means that the hat is actually awarded in the timeframe ranging from 24 Dec 2015 10:00 AM UTC to 25 Dec 2015 12:00 AM UTC.
This explains why it's currently 11.15 UTC and you've been awarded the hat already.
