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
How to use the weeks between dates
Use this weeks between dates to he exact number of weeks (and remaining days) between any two dates. Enter your values above and get your result in seconds. The tool is free, works on all devices, and keeps your data private — nothing is stored or shared.
How the weeks between dates works
The weeks between dates uses standard formulas used in scheduling, project planning, and deadline management. Enter your inputs, and the tool calculates the result instantly in your browser. No server-side processing means your data stays on your device. Results update in real time as you change inputs.
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.
Weeks between dates: how it works
Date and time calculations underpin project planning, legal deadlines, contract management, and everyday scheduling. This tool handles the arithmetic automatically, accounting for leap years, time zones, and calendar edge cases.
Who uses this tool?
Project managers, solicitors, HR teams, and individuals use it to count days, plan around weekends, and verify contract dates — any situation where getting the timing right matters.
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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 →