Weeks Between Dates
Calculate the exact number of weeks (and remaining days) between any two dates.
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How to use this calculator
- 1
Select the start date.
- 2
Select the end date.
- 3
The result shows the exact number of complete weeks and remaining days between the two dates.
Frequently asked questions
How many weeks is 90 days?
90 days = 12 weeks and 6 days (or 12.857 weeks).
How many weeks in a year?
A standard year has 52 weeks and 1 day (52.143 weeks). A leap year has 52 weeks and 2 days.
Can I calculate weeks for past dates?
Yes — if the end date is before the start date, the result shows the elapsed weeks and days with a minus sign.
How is this different from months between dates?
Weeks are exact multiples of 7 days, so weeks between dates is always a precise calculation. Months vary in length (28–31 days), making month calculations approximate.
Calculating weeks between two dates
Exact weeks vs approximate weeks
One week is exactly 7 days — no variation. 28 days = exactly 4 weeks. 56 days = exactly 8 weeks. This makes weeks the most precise "human-scale" time unit beyond days. Months and years vary in length.
Common week-based intervals
Pregnancy is measured in weeks (40 weeks total). Project sprints are typically 2 weeks. Pay periods are often 2 weeks (26 per year). School semesters: ~16–18 weeks. Lease terms often specified in weeks. Medical follow-ups: every 4, 6, or 8 weeks.
Why weeks beat months for scheduling
For planning 6–12 week intervals, weeks are more precise than months (which can mean 28–31 days). "Meet again in 6 weeks" = exactly 42 days. "Meet again in 1.5 months" is ambiguous.
Learn more from an authoritative source:
WikipediaMonths Between Dates
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →