All I have to say is that you should all get into the entertainment business!
My husband and I met at a small studio and we had plans one Saturday to get up really early and get in line for KISS tickets. We were both asked to come into work that day to open up shop and work. We explained what we were doing, and we were asked to come in anyway. So, we did and the VP bought us 7th row tickets to see KISS as a thank you.
At one job, if you have to give up vacation time due to work, you get reimbursed. There is rarely any asking to be done since vacation time is requested months off in advance and they know when you've bought tickets/hotels. Usually, something is worked out so that everyone is happy, and it usually is to the employees' benefit.
I've gotten bonus time off at a previous job for working weekends. I've been given nights in luxury hotels as thank yous.
My current job is different, as time off is approved way in advance and there is not a reason that would make anyone miss vacation as we are all cross-trained here. Well, except the time my boss had vacation planned and I ended up in the hospital. He didn't have travel plans but had to come in. I still feel bad about that.
Anyway, OP: Why on EARTH do you think you've done one single thing wrong? You've planned a fabulous birthday and it isn't your fault that the job got in the way. I'm so, so sorry it hasn't worked out for both of you, but that is no reason to feel down on yourself.