You're doing a tue/thu/sat three-day split, but I don't know what time of the day you train (if it's not consistent).
If you train Tuesday morning, I would eat tuesday morning until wednesday morning. If you train Tuesday at 8 PM, I would eat from Tuesday at 8 until wednesday at 8.
A couple guidelines to follow:
1) increase eating density 24h after you train (ideally proportionally to the difficulty of the session (e.g. deadlift singles day followed by heavy sparring vs. push-pull-squat day)).
2) Don't fast for much more than 24h at a time. 27h or whatever is fine, but don't fast from Sunday at 4pm to Tuesday morning (that's about 40h).
3) If you're in a 3-day split, you will have one odd day (EAT fast EAT fast EAT fast [??]). What you do with this day should depend on what your workouts are like. I suggest eating maintenance on that day (maybe even less).