Date difference
Weeks between dates
Count complete seven-day periods, started weeks and remaining days between two dates.
Difference
4 full weeks
What the two week counts mean
Complete weeks
The number of whole seven-day periods between the dates. Ten days equals one complete week and three remaining days.
Started weeks
Any non-zero remainder counts as another started week. Ten days therefore touches two seven-day periods. The calculation uses elapsed calendar days; it does not round dates to ISO week boundaries.