Weeks between dates:
count full weeks and leftover days

How to find the weeks between two dates

To find the weeks between two dates, count the days from the first date to the second and divide by 7. The whole-number part is the number of full weeks, and whatever is left over is extra days.

A week is always exactly 7 days, so this is the one calendar conversion that never changes. Months and years vary in length; weeks do not, which is why many contracts, courses and plans use them.

1. 1Find the number of days from the start date to the end date (end date minus start date).
2. 2Divide that number by 7.
3. 3Read the whole-number part as full weeks.
4. 4Multiply the full weeks by 7 and subtract from the total days to get the extra days.

A spreadsheet follows the same logic. Subtracting one date cell from another returns the days, and dividing by 7 returns the weeks. Make sure both cells hold real dates and not text, otherwise the subtraction returns an error or zero.

Worked example: 3 February to 19 July 2026

Suppose a training programme begins on Tuesday, 3 February 2026 and ends on Sunday, 19 July 2026. You want to know how long it lasts in weeks.

The decimal and the remainder tell the same story. The 0.714 left after 23 weeks is 0.714 × 7 = 5 days.

Now a second case where the weekdays matter. A course runs Monday, 2 March 2026 to Friday, 26 June 2026. That is 116 days, which is 16 weeks and 4 days elapsed. Yet students attend classes in 17 different Monday-to-Friday weeks, because the last Friday still belongs to a 17th week.

Inclusive, exclusive and calendar-week counts

The same two dates can give slightly different answers depending on what you are counting. Decide first whether you want elapsed time or the span an event covers.

Use elapsed time for notice periods, warranties and ages. Use the inclusive count when you are asking how many days an event occupies, such as a leave that starts on a Monday and ends on a Sunday. Use calendar weeks when a timetable is organised by week number.

Hotel and rental bookings show the difference clearly. Check-in on the 10th and check-out on the 17th is 7 nights, which is elapsed time. A conference that runs from the 10th to the 16th inclusive also covers 7 days. The dates differ, but both are exactly one week long once you decide what is being counted.

Days to weeks conversion chart

A common year is 52 weeks and 1 day, and a leap year of 366 days is 52 weeks and 2 days. This is why a date moves forward by one weekday each year, and by two after 29 February.

Months are not 4 weeks. An average month is 52 ÷ 12 = 4.33 weeks, so a plan that says "12 months" is about 52 weeks, not 48.

To use the chart, find the row closest to your day count, then adjust. For 120 days, the 100-day row shows 14 weeks 2 days, and the 20 extra days add 2 weeks 6 days, giving 17 weeks 1 day.

Turning weeks back into a date

The same arithmetic runs in reverse. To find the date that is a given number of weeks after a start date, multiply the weeks by 7 and add that many days. Because 7 days is a whole week, the answer always lands on the same weekday as the start.

That makes weeks easy to plan with. A 12-week plan, a 6-week trial or an 8-week notice all end on the same weekday they began, which is why they are popular for schedules that revolve around a weekly routine.

Pacing works the same way. If a 166-day programme has 95 lessons, divide 95 by 23.71 weeks to get about 4 lessons a week. If you only know a number of days, divide by 7 first and the same reading applies.

Which form of the answer to quote

There are two honest ways to state the gap: 23 weeks and 5 days, or 23.71 weeks. Use weeks and days in anything people will act on, such as contracts, handover notes and timetables. Everyone can picture 5 days; few people can picture 0.71 of a week.

Decimal weeks are better when you are going to multiply, for example a weekly cost of ₹1,800 over 23.71 weeks is about ₹42,686. Keep at least two decimals in that case, and round only the final money figure.

Whichever form you use, say which dates you counted and whether both ends were included. One sentence of context prevents most disputes about a day or two.

Mistakes to avoid when counting weeks

• Counting both end dates by habit. Monday to the following Monday is 7 days, which is exactly 1 week, not 8 days.
• Dividing months by 4 or multiplying weeks by 4 to get months. The factor is about 4.33.
• Mixing up a week number (such as week 12 of the year) with the number of weeks that have elapsed.
• Rounding 23.71 up to 24 and quoting 24 weeks when a contract or schedule cares about the 5 extra days.
• Ignoring the time of day when your start and end carry timestamps. A start at 6 pm and an end at 9 am are not a whole number of days apart.
• Forgetting that a range containing 29 February has one more day than the same range in a common year.

If you want the time left before a future deadline, the guide to weeks until a date covers that angle. For the raw day count or business days only, see the guides on days between dates and working days. You can also use the calculator on this page for the day-by-day check.