Time Between Dates Calculator
Enter the number of days between your two dates to instantly convert to weeks, months, years, and business days — with a clean weeks-and-days breakdown.
An average month is 30.44 days — not 30. Using 30 introduces a 5-day error over a full year.
30.44
average days per month (365.25 ÷ 12) — accurate month conversions
365.25
average days in a year, accounting for leap years
5/7
share of calendar days that are weekdays (business days)
Thinking about time more clearly
Every unit, from one count of days.
Make deadlines intuitive
'90 days' is harder to picture than '13 weeks' or '3 months'. Converting a timeline into the unit that fits the conversation helps stakeholders grasp it instantly. The calculator gives you every unit at once so you can pick the clearest.
Countdowns and milestones
Weddings, due dates, visa expirations, contract renewals — any milestone can be expressed in days. Months give a gut-feel sense of distance; weeks give a sense of urgency. Use both perspectives for planning and motivation.
Business days vs calendar days
Contracts and SLAs usually count business days, not calendar days. Since only about 5 in 7 days are weekdays, a 30-calendar-day window is roughly 21 working days — always confirm which one a deadline means before you plan around it.
How the Time Between Dates Calculator Works
Formula
Weeks = Days ÷ 7
Months = Days ÷ 30.44
Years = Days ÷ 365.25
Business Days ≈ Days × 5/7Find the days between your dates
Subtract the earlier date from the later one to get total days.
Enter that day count
Slide to the number of days in your range.
Read every unit at once
Weeks, months, years, business days, and a weeks-and-days breakdown.
The calculator divides your day count by 7 for weeks, 30.44 for months, and 365.25 for years — the average month and year lengths, which keep conversions from drifting the way a flat 30-day month does.
It also shows business days (≈ days × 5/7) and a 'W weeks and D days' breakdown, so you can express the same span in whichever unit is clearest for a deadline, countdown, or plan.
Frequently Asked Questions
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