Days Between Dates Calculator
Count the number of days, weeks, and months between two calendar dates.
Total Days
Weeks & Days
Approximate Months
How the Days Between Dates Calculation Works
This calculator measures the span between a start date and an end date. It converts both dates to a fixed point in time and divides the difference by the number of milliseconds in a day, giving you the exact number of whole days between them.
- Total days: the number of calendar days from the start date to the end date.
- Include end date: when enabled, both the start and end dates are counted, adding one extra day. This is useful for counting inclusive durations such as a hotel stay or a project running from one date to another.
- Weeks & days: the total is broken into complete weeks plus any leftover days.
- Approximate months: an estimate using an average month length of 30.4375 days, which accounts for the varying lengths of months and leap years.
Common Uses
Counting Down to an Event
Find out how many days remain until a deadline, holiday, birthday, or vacation.
Project & Contract Durations
Measure the length of a project, lease, or billing period in days, weeks, and months.
Tracking Milestones
Calculate how long ago something happened or how much time has passed between two events.
Note: This calculator counts calendar days based on the dates you enter and does not account for time zones or partial days. Use the results as a guide for planning purposes.