God’s requirement for a prophet is 100% accuracy. Always.
If they don’t have it, they are false prophets.
Where does it say that in the Bible? Deuteronomy 18:22 says that the test of whether a prophet is true or false is if a prophecy comes to pass or not, regardless of specific days/dates.
FWICS, the only one who lays claim to 100 percent precision is the Father, and specific days are His secret alone (Matthew 23:46, Mark 13:32).