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Calendar date offset

Date Calculator

Find the calendar date a given number of days, weeks, months, or years before or after another date. Month ends are clamped.

Your numbers

Date offset

Move a calendar date by days, weeks, months, or years. End-of-month days are clamped.

Resulting date

2026-02-28Saturday
How we got this
  1. Starting dateJanuary 31, 2026
  2. Offsetafter 1 months
  3. ResultSaturday, February 28, 2026
What we assumed
  • Month and year offsets clamp to the last valid day of the target month. January 31 plus one month is February 28 or 29, not March 3.
  • This is calendar-date math, not business-day math and not a duration in milliseconds.
Technical details

Method date-v1.0.0Data Manual inputs / fixed rules

Guide

Calendar offsets with month-end clamping

CostAnswer editorialIndependent calculator publisher

Add or subtract days, weeks, months, or years from a date. Month ends clamp: January 31 plus one month is not a fictional February 31. Weekends still count; this is not business days.

Days between versus offset

The same engine can answer “what date is 90 days from June 1” and related offsets. Inclusive versus exclusive counting in contracts is a legal question; this page uses ordinary calendar arithmetic.

Questions about this calculator

What date is 90 days from today?

Use days-from-today for “today plus N,” or this page if the start date is not today. Weekends are included.

Terms used here

Clamp
If a month does not have the same day number, the engine uses the last valid day of that month.

Practical tips

  • Lease “months” and bank “days” are not always calendar months. Read the document.

Limits and caveats

  • Exact calendar arithmetic. Not a business-day or court-holiday engine.

Results are for information. They are not legal, tax, medical, or financial advice. How the math is maintained · Report a wrong figure.

Engine notes

Rounding, versioning, and omissions that sit beside the guide rather than repeating it.

  • Calendar offsets. Days and weeks add whole calendar days. Months and years use end-of-month clamping on a UTC date-only value.
  • Not business days. Weekends and holidays still count. Use the Business Days calculator to skip them.
  • Not “from today” only. This tool starts from any date you pick. Days From Today is the shorter today-plus-N surface.

Calculation receipt

What each number here is

This answer is arithmetic on what you enter. No outside dataset is involved, so nothing here can go out of date.

Date arithmetic is defined by the calendar.

Next

People working through dates and hours usually need these next.

EverydayDays from todayThe calendar date that is N days from today, or N days ago. Weekends still count; this is not business days.EverydayBusiness daysCount workdays between two dates, or add workdays to a date. Federal holidays are optional.EverydayAgeCompleted years, months, and days from a birth date to a selected as-of date, including leap-day rules.EverydayPer diemFederal travel per diem for a trip in the continental U.S.: the GSA lodging ceiling for every night, meals and incidentals for every day, and a check of your actual room rate against the cap. Type a city or ZIP.EverydayTime durationsAdd or subtract hours, minutes, and seconds as durations. Negative results stay signed and normalized.EverydayTime cardAdd shift start, end, and unpaid break across one or more days, including overnight shifts. Overtime law is not applied.