A couple weeks ago, my supervisor approved my request to attend a full day work event next week. It's a conference with a keynote speaker, offered by my employer, that I attended last year also and really enjoyed. I find out today that she scheduled a meeting for us with our boss for an annual performance review at the same time as the keynote speaker. I asked if that could be rescheduled as I'd be missing the main talk, and she said no. Should I push back or accept I'll miss the most interesting part of the day? I get that our boss is hard to nail down, but this is a half hour that could be anytime in the next month, whereas the conference only takes place once a year and they pay for me to attend. Any thoughts on how I should approach this?