UnitShift

Date Calculator

Calculate the number of days between two dates, or add/subtract days, weeks, months, or years from any date.

There are 90 days between the two dates (0 years, 3 months, 1 days).

to
90
days
0 years, 3 months, 1 days
3
Total Months
12
Total Weeks
90
Total Days
2,160
Total Hours

Popular Date Calculations

90 days from today180 days from today365 days from today30 days from today60 days ago6 months from today12 weeks from todayDays until ChristmasDays until HalloweenDays in FebruaryDays in 2026Days until Summer

Days Until Holidays

Christmas: 301 daysNew Year's Day: 308 daysValentine's Day: 352 daysHalloween: 246 daysIndependence Day: 127 daysNew Year's Eve: 307 daysSt. Patrick's Day: 18 daysMother's Day: 73 daysFather's Day: 108 days

Days in Each Month

January: 31February: 28March: 31April: 30May: 31June: 30July: 31August: 31September: 30October: 31November: 30December: 31

Frequently Asked Questions

How do I calculate the number of days between two dates?

Enter your start date and end date in the "Days Between Dates" mode above. The calculator subtracts the earlier date from the later date and shows the result in days, weeks, months, and years.

How do I add or subtract days from a date?

Switch to "Add / Subtract Days" mode. Enter a start date, the number of days (or weeks/months/years) to add or subtract, and the calculator will show the resulting date.

Does this calculator account for leap years?

Yes. The calculator uses standard JavaScript date arithmetic, which correctly handles leap years (every 4 years, except centuries not divisible by 400) and varying month lengths.

What is the formula for days between dates?

Convert both dates to their numeric timestamp values, subtract, then divide by 86,400,000 (the number of milliseconds in one day). This gives you the exact number of calendar days between the two dates.