Weeks Between Dates Calculator
Split the elapsed calendar time between two dates into full seven-day weeks and leftover days. Same midnight-to-midnight span as Days Between Dates — just grouped by sevens — not a count of Monday-start diary weeks.
How to use
- Set the start date (leave date, contract start, or the first midnight you care about).
- Set the end date. A later end is a positive span; an earlier end is the same length in the other direction.
- Read full weeks first, then leftover days, plus the raw day total.
- Add 1 yourself only if you need how many calendar dates appear including both ends. Use Business Days to drop Saturday and Sunday.
How it works
A week on this page is seven civil days, not “the week of 6 January” printed in a planner. 1 January to 8 January is seven elapsed days, shown as 1 week and 0 leftover days. 1 January to 16 January is 15 days: 2 weeks and 1 day. The start date is not counted as a unit of duration — neighbouring dates are 0 weeks and 1 day.
That is the same elapsed-day method as Days Between Dates. This page leads with weeks because people plan sprints, notice periods and “how many weeks pregnant” style questions in sevens. It does not snap to Monday or Sunday. A Wednesday-to-Wednesday span of seven days is still 1 week, even though it is not a labelled ISO week.
Leap days that sit inside the span add one calendar day, which can change the leftover remainder. 28 February 2024 to 7 March 2024 is 8 days (1 week and 1 day) because 29 February existed. The same labelled dates in 2023 are 7 days (1 week). The tool does not use a 30-day bank month or a 52-week commercial year.
Inclusive “how many week-commencing dates appear on the wall” is a different question. If an event is advertised as running week 1 through week 4, that is four labelled weeks, not necessarily 28 elapsed days from the first Monday. Add 1 to the day count only when you want inclusive dates, then divide if you must — this calculator will not do that rewrite for you.
Weekends stay in the span. For Monday–Friday only, use Business Days, which is inclusive of both ends and still ignores holidays. For calendar months with day-of-month clamping, use Months Between Dates. For clock hours, use Time Duration.
Formula
Weeks = floor(|end − start| ÷ 7) Leftover days = |end − start| modulo 7
Worked examples
One week later
2024-01-01 to 2024-01-08 → 1 week (7 days)
A fortnight plus a day
2024-01-01 to 2024-01-16 → 2 weeks and 1 day (15 days)
Useful notes
- Same elapsed-day method as Days Between Dates, displayed in weeks first.
- A week is seven calendar days, not a Monday–Sunday work week.
- Weekend days are included. Use Business Days if you need weekdays only.
FAQ
- Does a week start on Monday?
No. The count is seven calendar days from the start date, regardless of weekday.
- Is the start date included?
No. Neighbouring dates are 1 day (0 weeks and 1 day). Add 1 yourself if you need an inclusive count of dates.
- How is this different from days between dates?
The underlying span is identical. This page leads with weeks and leftover days; the other leads with the day count.
- Is this ISO week numbers?
No. It does not report week 1–53 of a year. It only divides elapsed days by 7.
- Do leap days change the week count?
They change the day total by one when they sit in the span, which can add a leftover day or roll another full week.
Guides
Related tools
Days Between Dates
Count how many calendar days separate two dates, including the week-and-remainder breakdown.
Months Between Dates
Count whole calendar months between two dates, plus leftover days and a years-and-months split.
Business Days
Count weekdays between two dates, excluding Saturday and Sunday. Public holidays are not removed.
See all Date & Time tools.