Date Calculator (Add / Subtract Days)
Need to know what date falls 30, 90 or 180 days out — or what the date was some days ago? Enter a base date, a number of days and the direction to get the date and the weekday.
Your numbers
Result
- Day of the week
- —
How it works
The calculator moves forward (or back) by the given number of calendar days from the base date and shows the resulting date and its day of the week. Adding 30 days to Jan 1, 2026 lands on Jan 31, 2026. Month and year rollovers are handled automatically.
Calendar days, not business days
The count is in calendar days — it includes weekends and holidays. For deadlines that only run on working days (many legal and commercial terms), use the business-days calculator instead.
Common uses
Find the end of a term (a 90-day warranty, a 60-day note), a follow-up appointment, the end of a trial period, or simply answer "what date is X days from now". Going backward, it finds when something started that has lasted a given number of days.
Frequently asked questions
Sources
- Calendar arithmetic (calendar days)
Embed this calculator
Copy the code and paste it into your site or blog. Credit with a link back to Contania is included, and the height adjusts itself.
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<script>window.addEventListener("message",function(e){if(e.data&&e.data.type==="contania:embed-height"){var f=document.querySelector('iframe[src="https://contania.app/embed/date-time/date-calculator"]');if(f){f.style.height=e.data.height+"px"}}});</script>Related calculators
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