I think we're still missing a night here. Let's break it down:
1) Part of Friday day = day 1
2) Friday night = night 1
3) Saturday day = day 2
4) Saturday night = night 2
5) Sunday morning = day 3
Day 3 is tricky. Matthew has the ressurection before sunrise which means no day 3. Mark has it in Sunday morining so there is a day 3. Luke has it very early in the morning so there is a day 3. John has it before sunrise on the first day so it's still the Sabbath and so no day 3. But let's be generous and give you that third day.
Since Jesus was already ressurected on the third day there was no third night. Zero does not round up to one.
1) Part of Friday day = day 1
2) Friday night = night 1
3) Saturday day = day 2
4) Saturday night = night 2
5) Sunday morning = day 3
Day 3 is tricky. Matthew has the ressurection before sunrise which means no day 3. Mark has it in Sunday morining so there is a day 3. Luke has it very early in the morning so there is a day 3. John has it before sunrise on the first day so it's still the Sabbath and so no day 3. But let's be generous and give you that third day.
Since Jesus was already ressurected on the third day there was no third night. Zero does not round up to one.
If God wanted us to be Atheists we'd be born that way.

