I'm currently going into an interview this Wednesday with the USPS for a Custodial Laborer job, the days I work are Monday and Tuesday, Thursday thru Saturday. However my wife and I also do wedding photography on the side, and we have 3 different saturdays over the next 5-6 months where we have weddings. 3 total not 3 per month.

I want to inform my potential employer of this, but am worried if I do it at the interview that they won't want to hire me, but if I find out they want to hire me they may be more willing to work with me, especially if I switch my days off that week.