The answer is going to be very employer and employee dependent. But you know this.
I work for a non-profit (no paid volunteer time for working other interests) AND I work every other weekend (Fr-Mo). But my six 12 hours shifts are sorta bunched into one week of a two week pay period. So as long as events are on my “off” weekend, all is good!
This season, we went to an away regional, home regional, and Worlds. Lucky for me, two of the three were on my off weekend! I took PTO for the other event where I was scheduled to work. …I actually have my calendar blocked off every other weekend a year+ in advance so I can better plan. Not sure how you’re doing a Regional in two days though, I spend at least four days and more if there is serious traveling involved.
We also have the offseason comps, demos, state fair, etc. Those are less important to me and I attend when I’m able and don’t worry much about those I can’t.
But to answer your real question: how to convince employer to provide volunteer time.
If it’s difficult now, you need to change the culture of the company. Advocate, advocate, advocate. Show the benefits the students provide to the community and their future. How can that benefit your employer today and tomorrow.
Or, better consider the perks and benny package when next looking for a new employer. If FIRST events are important enough to you, ensure your new employer supports that or at least doesn’t inhibit. I understand looking for a new job is a bit extreme, but if you’re in the market, make sure your FIRST “wants” are negotiated BEFORE you’re hired.
If your four boys become interested (hopefully) in FIRST, you’ll have even more events to deal with! YIKES!!