What should I tell the attorney I’m clerking for about my vacation plans?

Rising 2L. Im currently in the hiring process right now for a law clerk job with a very chill, nice attorney, the attorney hasn’t officially told me directly that I’ve been hired but the firms HR office called me today to confirm my availability and start date (beginning of June). The HR rep then said they’d be sending me an offer letter soon I guess… meaning that I got the job, right??

I have plans to go to a music festival on June 12-15th… meaning I’d have to take off Thursday, Friday, and probably the following Monday.

That’s a lot of time to take off basically right at the start of my job. The attorney is nice and I’m sure if it was for like a more valid reason to be missing work they’d have no problem with it, but I’ve been wanting to go to this music festival for yearsss and have already spent so much money between the ticket and everything.

I haven’t even been officially hired yet but what should I do? Would it be fine to be honest with the attorney and ask them to take time off for this? Should I do that right now?

This probably seems very unprofessional. I get that. But I don’t want to lie and come up with some other excuse for him, but I also really don’t want to have to miss any days of the festival. I can leave the festival early and try to be back on Monday (it’s a 7 hour drive from me), but we’ll see…