Dudes,
Take the earliest class date, even if it's a 2 year tour driving the lav truck at a Crimea TU-95 domicile.
20 years later, you'll be kicking yourself after watching the guy hired 1 week before your grab the last Xmas, 4 July, your kids wedding, anniversary, little league world series lines with days off.
I delayed my interview date almost 25 years ago and kick myself after every months bid and the yearly vacation bid. Delaying a seniority number date, is only exceeded by marrying your second Flight Attendant.
Seriously, this is "listen to Yoda chit."