CalcLoft
Everyday

Date Calculator

Result
59 days
from 2026-01-01 to 2026-03-01 — that's 8 weeks 3 days.

This date calculator counts the days between two dates or adds and subtracts days from a date. Between Jan 1 and Mar 1, 2026 is 59 days; add 90 days to a date to find a deadline. It counts whole calendar days in UTC, so leap years are handled and the result is never thrown off by daylight saving time.

The formula

days = (end − start) ÷ one day; new date = start ± days

A day is a fixed 86,400 seconds in UTC. Subtract the two dates and divide to count days, or add a day count to a date's timestamp to shift it forward or back.

How to use it

  1. 1

    Choose count or add/subtract

    Pick days between two dates to measure a gap, or add or subtract days to shift a date.

  2. 2

    Enter the dates

    Use the date fields in YYYY-MM-DD form. For add/subtract, enter one date and a number of days (negative to go backward).

  3. 3

    Read the result

    You get the exact day count between two dates, or the resulting calendar date when adding or subtracting.

Frequently asked questions

Does it count both the start and end dates?
It counts the gap, so the start date isn't included. The same date returns 0 days and consecutive days return 1 — add 1 if you need both ends counted.
Are leap years handled?
Yes. The calculator counts real calendar days, so a range spanning February 29 includes that extra day automatically.
Can I add days across a month or year boundary?
Yes. Adding 45 days to January 20 correctly lands in March, rolling through the month and year boundaries for you.

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Part of Everyday Calculators. Last updated 2026-06-14.