I assume by "bank" you guys mean roll over to the next year.
We can't roll our vacation time over. Throughout the year we are allowed to sell out up to 2 weeks any time we want. Any other left over is paid out first pay in January.
We have to hold a few vacation hours for scheduled shutdowns. How many is determined by your department/schedule. The 12 hour production folk need to hold onto more vacation hours for Christmas shutdown than I do on an 8 hour schedule.
That all said, I use to use them all up. Last year for 20 years I gained my 5th week. I also got a divorce, I'm basically homeless for the past year and a half and my living situation is far from ideal.
I sold 1 week back to finish paying the lawyer. 2nd week paid back to finish paying off a credit card. I had 2 weeks paid out at the beginning of this year to put in the bank to start the savings for a place to live. All I'll be able to afford is a falling apart $10,000 trailer, but at least I'll have a place to cook, fridge and freezer to hold food, and I won't be criticized daily about how hot of a shower I take or how I brush my teeth or blamed for every crumb that is found in the kitchen (I don't even use the kitchen because of the criticism.) About to squeeze my head in a vice about right now as it would be more comfortable than living where I am (mother's house.)
So I took a sprinkling of vacation days here and there throughout the year to cover the kids' school programs but that's it. I'm broke, can't provide a home for my children, and can't do anything but sit and stare at the walls on days off. I can't stand right now not being at work on the weekends let alone to take extra time off.