The average of the two dates
The calculator averages the two dates and converts the result back to a calendar date. Dates are treated as date-only values, so time of day and daylight-saving changes never shift the answer.
Date Lab
Date Midpoint Calculator
Calculate the exact midpoint date between two calendar dates with a transparent browser-based method.
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What you get
How the midpoint between two dates is found
Enter a start date and an end date, in either order. The calculator finds the calendar date exactly halfway between them and reports it together with the total elapsed days and the length of each half — useful for project timelines, anniversaries, and scheduling around a central date.
Worked example: a 200-day span
From 1 January 2026 to 20 July 2026 is exactly 200 days. Half of 200 is 100, and 100 days after 1 January is 11 April 2026 — the midpoint the calculator returns, with 100 days in each half.
Odd spans and other boundaries
When the span has an odd number of days, the true halfway moment falls at midday. For 1 March to 8 March 2026 (7 days), the calculator shows 4 March, with a 3-day first half and a 4-day second half. If both dates are the same, the midpoint is simply that date.
How it works
One calculation, with the rule visible
This tool keeps the input dates, counting convention and result together so the answer can be checked.
Start date
Enter the first date of the span, in either order — the two dates can be swapped without changing the result.
End date
Enter the second date. Dates are treated as date-only values, so time of day and daylight-saving changes never shift the answer.
Average the two dates
The calculator averages the two dates and converts the result back to a calendar date, reporting the total elapsed days and the length of each half alongside.
Read the midpoint
1 January to 20 July 2026 spans exactly 200 days, so the midpoint is 100 days in: 11 April 2026, with 100 days in each half. On an odd span the true halfway moment falls at midday — 1 to 8 March 2026 shows 4 March, a 3-day first half and a 4-day second half. If both dates are the same, the midpoint is that date.
Method & limits
What this result means
A useful answer includes both the number and its assumptions.
Calculation method
Date Midpoint Calculator calculates the exact midpoint date between two calendar dates using Gregorian calendar arithmetic. Dates are treated as date-only values, avoiding accidental time-of-day and daylight-saving shifts.
Important: Weekend, holiday, legal, medical, financial, school or workplace policies are included only when the tool explicitly asks for them. Confirm official decisions with the responsible authority.
Odd spans: which half gets the extra day
The calculator counts the elapsed days between the two dates, halves that count, and adds the result to the start date. On an even span the halves are equal. On an odd span the count cannot be split evenly, so the whole days are divided as evenly as possible — the first half takes the smaller share — and the exact halfway moment falls at midday on the date shown. That is why the 1 to 8 March example produces halves of 3 and 4 days rather than 3.5 and 3.5. Note the counting convention: the start date is day zero and the count measures elapsed time. A plan or contract that counts both the first and the last day as full days is working with a span one day longer, and its middle day can fall one day later than the date shown here — check which convention your document uses before treating the midpoint as a deadline.
Time of day is ignored, on purpose
Both inputs are calendar dates, and each is treated as a whole day. Daylight-saving changes make some local days 23 or 25 hours long in clock time, but they never change how many calendar days sit between two dates, so they never move the midpoint. If an interval is genuinely defined by timestamps — a 72-hour equipment hire, a connection measured in hours — its halfway instant can sit up to half a day away from the date midpoint. For anything planned in whole days, which is what this tool is for, the date midpoint is exact.
Halfway between two dates is not the middle of a list
With two dates, the midpoint and the average are the same thing. With several dates they are not. The halfway point of a range — halfway between the earliest and the latest date — usually differs from the median, the date in the middle of the list. For events on 1, 2 and 31 January, the range midpoint is 16 January while the median is 2 January. This calculator returns the range midpoint of the two dates you enter; the middle value of a longer list cannot be found by entering its first and last dates here.
Common checks
- Confirm day, month and year before calculating.
- Check whether endpoints should be included.
- Review February 29 and month-end cases.
- Save the reference date with the result.
Edge cases worth knowing
- Leap years: a span that includes 29 February is one day longer than the same calendar span in a common year. 1 February to 1 March is 29 days in 2028 and 28 days in 2026, and the full leap-year span from 1 January 2028 to 1 January 2029 (366 days) has its midpoint on 2 July 2028.
- Crossing a year boundary: nothing changes in the arithmetic. 15 November 2026 to 15 February 2027 is 92 days, and the midpoint of that span is 31 December 2026.
- Reversed order: entering the later date first returns the same midpoint — the pair is ordered before it is halved.
- The same date twice: the span is zero days and the midpoint is simply that date.
Want the reasoning behind the method? Read Finding the Midpoint Between Two Dates — the step-by-step guide with worked examples, odd-span handling, and common mistakes to avoid.
Worked examples
Three midpoints, worked in full
Each example can be checked against the calculator: enter the same two dates and the same midpoint comes back, together with the length of each half.
Splitting a project into two phases
A project runs from 12 January to 8 May 2026 — 116 days in total. Half of 116 is 58, so the midpoint is 11 March 2026, with 58 days before it and 58 days after it: a natural date for a mid-project review or a phase handover.
The halfway point of a pregnancy
Counting 280 days from a last-period date of 1 February 2026 gives a due date of 8 November 2026. The midpoint of that span is 21 June 2026 — exactly 140 days in, the 20-week halfway mark. If dating from a scan shifts either date, the midpoint shifts with them.
The middle of a one-year contract
A contract running from 1 April 2026 to 31 March 2027 spans 364 days. Half of 364 is 182, and 182 days after 1 April is 30 September 2026 — the exact middle of the term, and a sensible date for a mid-term review.
Common questions
Date Midpoint Calculator FAQ
Answers about method, odd spans, order and boundaries.
How is the midpoint between two dates calculated?
The calculator averages the two dates: it counts the days between them, halves that number, and adds it to the start date. From 1 January to 20 July 2026 is 200 days, so the midpoint is 100 days in: 11 April 2026.
What happens when the span has an odd number of days?
The true halfway moment falls at midday. The calculator reports a calendar date: for 1 March to 8 March 2026 (7 days) it shows 4 March, with a 3-day first half and a 4-day second half.
Does it matter which date I enter first?
No. The two dates can be swapped without changing the result.
What if both dates are the same?
The midpoint is simply that date.
Do time zones or daylight saving affect the result?
No. Dates are treated as date-only values, so time of day and daylight-saving changes never shift the answer.
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About the author
Navjeet Kamboj
Navjeet Kamboj is the author and editor of Age Calculator Lab. He focuses on making age, date, milestone and planning calculations easier to understand through clearly explained methods, practical examples and responsible limitations.