Absolutely, do what works for your schedule. My fasting regimen is different on the weekends and it works well! Think about fasting as more of time-restricted feeding and that window is flexible. That is the beauty of IF!
My schedule is similar. I do 18-20 hour fasts M-Thurs. Usually 14 hours on Friday and Saturday so I can have dinner with friends and family and Sunday is up in the air. Sometimes 18-20 and sometimes closer to 14 hours.
It may take longer to hit my goals, but this is a marathon not a sprint and I’m ok with it. Even with this schedule I”m losing roughly 1lb per week. The best plan is one that you’ll stick with long term. If you miss some fasts, accept it, move on and try to do better next week.