Calendar desk
Weeks Between Dates
Count complete seven-day periods between two dates.
Weeks Between Dates: Count how many complete seven-day periods fit between a starting date and an ending date. The page also shows the full signed calendar-day difference, so a discarded partial week remains visible. It measures elapsed date intervals rather than counting the named calendar weeks that a range touches. Runs 100% locally in your browser with zero server file uploads.
- Category
- Calculators
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Whole weeks
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- Calendar days
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Whole weeks = trunc((end date − start date) ÷ 7); remaining days are not counted- Dates are calendar dates at UTC midnight; no local timezone or daylight-saving adjustment is applied.
- Results are planning utilities. Public holidays, locale-specific work rules, and company policies are not inferred.
- A partial week is discarded toward zero; reverse dates return negative whole weeks.
Complete-week formula with a remainder
Represent Start date S and End date E as consecutive day numbers. Calendar-day difference D = E − S, and whole weeks W = trunc(D ÷ 7), where trunc discards the fractional part towards zero. For a forward range, leftover days can be found as D − 7W; this page reports D itself rather than that remainder.
From 2025-01-01 to 2025-01-12, D = 11 days. Dividing gives 11 ÷ 7 = 1 + 4/7, so W = 1 whole week. The widget displays 1 whole week and 11 calendar days. The four-day partial week is present in the day total, but it cannot contribute another complete week.
Elapsed weeks versus week labels
No extra date is included simply because both endpoints are entered. A same-date comparison returns zero elapsed days and zero weeks. For an inclusive list of dates, count the listed dates separately; that is a different question from the distance between them.
ISO's public date-and-time overview (https://www.iso.org/iso-8601-date-and-time-format.html) covers standard date representation. If you need an ISO week label for each endpoint, use the ISO week number tool rather than subtracting labels. Labels restart at a week-year boundary, whereas consecutive day numbers continue through it.
How to use it
- Enter the beginning and ending dates of your interval.
- Calculate the number of whole seven-day periods.
- Read the calendar-day total to judge whether a partial week was discarded.
Privacy & limitations
Dates, times and results stay in your browser. No inputs are uploaded.
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Frequently asked questions
Will crossing a Sunday-to-Monday boundary count as a full week?
No. Only seven elapsed date steps make one full week here. Touching two different calendar weeks can still be an interval shorter than seven days.
Why are leftover days absent from the whole-week result?
The division by seven is truncated towards zero. The total calendar days still includes the entire interval, but the whole-week output does not display a fractional week.
What if my end date is earlier than the start?
The calendar-day total becomes negative and whole weeks carry that direction. A reversed span of less than seven days gives zero whole weeks, because no complete seven-day period fits.
Free tool · runs in your browser · no account required