As long as you remember to log in and get the ticket before they stop being given to characters you can save and use them whenever you like.
I still have some tickets I haven't used from years ago and they still work.
Good Point that sometimes is overlooked over the years:
Always
log-in your characters on all shards to collect any type of gift ticket or reward
since many of gifts must drop into your character's back pack or bank.
Be sure not to over-load your storage mules and their storage-type-bank accounts so they can accept that extra ticket/gift when you do log in. Else they would probably get a message reguarding overload or lack of same.
- - oh yes .. and in addition:
This year be sure to expect any of your Tamers that own Dread Warhorses to be hit by that new bug: Random Deadly Poison Bug - - an Area Spell that hits when you log-in, and sometimes after many safe log-ins, or even after being on line a long time after log in.