Date Difference Calculator
Find the calendar and total-day difference between two dates.
Choose both dates.
What this calculator does
Compare any two valid dates in years, months, days, total days, and weeks.
Inputs and what they mean
- Start date
- — date value.
- End date
- — date value.
- Always show a positive difference
- — yes/no value.
How to use it
- Choose a start and end date.
- Choose whether reversed dates should stay negative.
- Read total days and the calendar breakdown.
Formula
Total days = (end date − start date) ÷ 86,400,000 milliseconds; calendar difference also accounts for actual month lengths.
Worked example
Difference across one month
January 1 to February 1 is 31 days.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.
Common questions
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