How to Calculate Weeks Between Dates
What is Weeks Between Dates?
A weeks between dates calculator counts the number of full and partial weeks separating two dates. Used for pregnancy tracking, project planning, subscription billing, and event scheduling.
Formula
weeks = days_between / 7 (integer or decimal depending on requirement)
- start
- Start date (date) — Beginning date
- end
- End date (date) — Ending date
- weeks
- Weeks between (weeks) — Number of calendar weeks (may be decimal)
Step-by-Step Guide
- 1Calculate total calendar days between dates
- 2Full weeks = floor(days ÷ 7)
- 3Remaining days = days mod 7
- 4Partial weeks = total days ÷ 7 (decimal)
Worked Examples
Input
14 days apart
Result
2 full weeks, 0 remaining days
Input
40 weeks pregnant
Result
280 days = full term
Input
1 year = 365 days
Result
52 full weeks, 1 remaining day
Frequently Asked Questions
What is a calendar week?
Generally 7 calendar days. ISO weeks are standardised Monday–Sunday, with specific rules for week 1.
How many complete weeks between two dates?
Divide total days by 7 and round down. Example: 15 days = 2 complete weeks plus 1 day.
How are partial weeks counted?
Depends on context. For billing or planning, partial weeks are often counted as full weeks. Check requirements.
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