That’s what’s great about IF. You get to decide this. Do whatever feel best for you. There’s no right or wrong answer here.
If it was me personally, I would probably have a light lunch a little later on Friday then go out and enjoy the evening with friends without even stressing about the timing that much. Then just get back into my routine the next day.
Personally, these are the days that I switch to CICO.
To hold off on your window Friday, you will have extended your Thursday fast to 23hours, but you’re still only doing a theoretical 13.5 hr fast going into Saturday. Times start to get funky.
Just be aware of what you’re eating. Maybe instead of a full lunch to break your fast, you just have a bowl of soup or something. Then maybe a small snack if you just can’t get through until dinner. Eat, drink, be merry with your friends. Wake up Saturday and back on schedule. you might even find that you’re not all that hungry since you ate late, and you can pull an OMAD to “right the ship”.
Don’t stress about it. and don’t deny yourself socialization based on your diet. It will all work out in the long run. 1 yr committed fast, 1.5 yr maintaining, still down 100 lbs.