If you actually studied the culture of those times, the term, as it began to dawn on the first day of the week meant the Sabbath was ending, which would have been at dusk, since that is how that culture counts time and still does to this day.
Acts 20:7
On the first day of the week, when we were gathered together to break bread, Paul talked with them, intending to depart on the next day, and he prolonged his speech until midnight.
This confirms the day started at sunset, and it makes perfect sense Paul came to them right after the sun went down and spoke with them until midnight, as it would be insane for Paul to give an almost 15hr message from 6am-midnight.
As usual, whenever something is actually explained in context in Christianity to make the actual text add up and prove why you believe what you believe, folks dont care or it doesn't matter it if doesn't fit their narrative.
He was in the grave 3 days and 3 nights, so that rules out a Friday crucifixion as well, but thats a whole different topic that has been discussed and addressed here many times.