Calcowa calculator and converter logo
Date & time calculator

Date Calculator

This date calculator adds or subtracts days, weeks, months, or years from any date. Pick a starting date, choose how far to jump, and you'll get the result date with its weekday and how far away it sits. It's how you'd answer questions like what date is 90 days from today, or what day falls 6 weeks before a deadline. There's also a days until mode for a countdown, and it's free and private.

  • Add or subtract dates
  • Days, weeks, months, years
  • Result date & weekday
  • Days until a date
  • Forward or back

Last updated June 17, 2026 Leap years handled Reviewed by the Calcowa team

Month and year jumps roll over correctly, and leap years are handled.

Result detail live
Day of weekTuesday
Days from today90
Full dateSep 15, 2026
Result date
Sep 15, 2026 result date

Weekday
Tuesday
Days away
90
Working

today + 90 days = Sep 15, 2026

The basics

What date is 90 days from today?

Ninety days from today is roughly three months out, but the exact date shifts depending on the months in between, since they run from 28 to 31 days. Rather than count squares on a calendar, this date calculator turns the start date into a day number, adds the days you ask for, and converts it back, so the answer is right every time. The same approach answers 30, 60, 180, or 365 days from today, and it works backward too. Switch the unit to weeks, months, or years when that fits the question better, and you'll always see the weekday alongside the date.

result = start date ± amount
Step by step

Adding 90 days, step by step

Here's how the tool jumps 90 days from a start date. It's the same idea you'd use on a calendar, just without the counting:

  1. 1

    Set the start datePick your base date, or leave it on today for the most common case.

  2. 2

    Choose the jumpAdd 90 days, or switch the unit to weeks, months, or years.

  3. 3

    Roll across monthsThe tool carries across month and year ends, so the result lands on the right day.

  4. 4

    Read the date and weekdayYou get the full date, the day of the week, and how far away it is.

Quick reference

Common day jumps

Here's roughly how the popular day amounts translate into months, which is useful for a quick gut-check. They're approximate, since months aren't all the same length, so the tool gives you the exact date.

DaysRoughlyWeeks
30 daysabout 1 month4.3
60 daysabout 2 months8.6
90 daysabout 3 months12.9
180 daysabout 6 months25.7
365 days1 year52.1
FAQ

Frequently asked questions

Count 90 days forward from today and you'll land about three months out, since 90 days is close to a quarter of a year. The exact date depends on which months you pass through, because they're different lengths, so this date calculator does the counting for you. Type 90, pick days, and you'll get the precise date and the weekday, no calendar flipping required.

Start from your base date, choose add, type the number of days, and read the result. The tool rolls over month and year ends for you, so 25 days after December 20 correctly lands in January. You can switch the unit to weeks, months, or years too, which is handy for due dates, deadlines, notice periods, and renewals.

Flip the toggle to subtract and enter the amount, and the tool counts backward. So 30 days before a deadline shows you the date you'd need to start, and a year before an anniversary gives you the original date. It handles leap years and month lengths, so you don't have to second-guess February or a 31-day month.

Adding months keeps the same day number and moves the month forward, so March 15 plus two months is May 15. When the day doesn't exist in the target month, like January 31 plus one month, it rolls into early March, which is the standard behavior. For an exact day count instead, switch the unit to days and the tool counts them straight through.

Switch to the days until mode, pick your target date, and you'll see how many days, weeks, and months are left from today. It's a quick countdown for a holiday, a birthday, a wedding, or a deadline. If the date has already passed, the tool shows how long ago it was instead, so it works both forward and backward.

Yes on both counts. There's no sign-up, no usage limit, and nothing to install, since the whole thing runs in your browser. The dates you enter stay on your device and aren't sent anywhere. Bookmark it and you've got a fast way to add days, subtract days, or count down to a date whenever you need one.

Keep going

Related calculators

More tools for dates and time.

Planning ahead?

Jump to any date above, or browse all date and time tools.

Date & Time