Weeks between dates
Count the number of weeks (and leftover days) between any two dates — as complete weeks, as an exact decimal, and as calendar weeks crossed.
Weeks, three ways
“How many weeks between March 3 and April 18?” has three honest answers, and which one you want depends on the job:
- Complete weeks + days — best for durations: “6 weeks and 4 days of lead time.”
- Exact decimal — best for rates and averages: “we ship every 2.4 weeks.”
- Calendar weeks crossed — best for planning boards: if the dates land in ISO weeks 10 and 16, they are 6 calendar weeks apart even when the day gap is a little more or less than 42 days.
For the calendar-week view it helps to know each date's week number first — get it from the week number calculator or the year charts.
Frequently asked questions
How are the weeks counted?
Three ways, shown side by side: complete 7-day weeks between the dates (with leftover days), the exact decimal value (days ÷ 7), and how many calendar-week boundaries (Mondays) are crossed.
Does the count include the start and end day?
The tool counts the days between the two dates — the difference, the same way spreadsheets subtract dates. From Monday to the next Monday is 7 days = 1 week.
Can I count only working weeks?
This tool counts all weeks. For sprint-style planning by week numbers instead, see sprint cadence by week numbers.