That puts it on Monday. By why quibble when none of the other Disciples believed He would rise by Sunday morning.
Thats looking at "three days" as he whold rise after being dead 72+ hours
I would look at "in three days" as
he died on Fri. some time before sunset (day 1 / the Day before the Jewish Sabbath)
then Sat.(day 2 / Jewish Sabbath/ end of thet week)
And rose on Sun.(any time after sunset Sat.) (day 3 / the Day after the Jewish Sabbath/first day of the week)