Date Time Calculator to Add or
Subtract Time Spans To/From Dates

[ Skip to Calculator ] Calcy pointing down

The online Date Time Calculator on this page will quickly add or subtract spans of time to or from a date of your choosing!

This free online date calculator will subtract or add days, weeks, months, years, hours, minutes, and seconds from or to the date and time you select.

Note that if you would like to find the number of days between two dates, or the number of days left until a certain date, please visit the Date Difference Calculator.

Number of Uses Only Limited By Your Imagination

Want to find out what the date will be when a 30, 60, 90, 120, 180, 365, or 500 day event is set to occur?

Simply select today as the starting date, now as the starting time, add as the operation to perform, and enter the desired number of days to add to the date, and the calculator will tell you the resulting date -- along with the time and day of the week.

Or, do you want to know what the date was a given number of days, weeks, months, or years ago? No problem. Just select today as the starting date, select subtract from the operation menu, enter the number of time spans to subtract, and click the "Calculate Date" button!

Here are just a few of the many questions the time date calculator can help you to answer:

  • On what day will my 90-day warranty expire?
  • On what day is my 60-day note due?
  • What day does my 30-day free trial expire?
  • What day will it be 100 days from today?
  • What day will it be 500 days from now?
  • If we met on this date, on what day will our 6-week anniversary fall?

With that, let's use the date time calculator to calculate what date it will be after adding or subtracting one or more spans of time.

Date Time Calculator
Calcy sign introducing Date Time Calculator

Instructions: Select the month and day and enter the 4-digit year for the starting date.

Next, select the optional starting time (hours, minutes, seconds) and then select "Add" or "Subtract" for the date math you would like performed.

Finally, enter the number of date and time units you would like added or subtracted from the starting date, then click the "Calculate Date and Time" button.

Mouse over the blue question marks for a further explanation of each entry field. More in-depth explanations can be found in the glossary of terms located beneath the Date Time Calculator.

calcy treasure chest of features Save Your Work!

Just one of the Treasure Chest of Bonus Features you'll enjoy when you support the Ad-Free, Member Version of this site (for as little as 58¢ per month). Watch the Video Tour to see what you're missing!

Calculator Not Working? Please try disabling Ad Block for this page, as it may be blocking the code that runs the calculator.

Help Date (Time ):
Days Hours
Weeks Minutes
Months Seconds

Help Date result:
Please grade my work and help me improve:
If you liked this page, please share it, or give it a Like, +1, Tweet, or Pin.
calcy image pointing right

Date Time Calculator Glossary of Terms

Calcy magnifying glass

Check Out My Other Super
Calendar, Time, and Date Calculators
To Help You calculate ...
Super Calcy

Date (Time): Select the month and day and enter the 4-digit year of the starting date. Note that the starting year must be greater than 0 and less than 4000. If you want to set a starting time (optional), change the hour, minute, and second selection to the desired time (or use time dropdown menu to set a general time of day). Changing the selection back and forth from the Now option to another option will update the time setting to the new Now time.

Add or Subtract time spans: Select Add or Subtract and enter the number of each date and/or time unit you would liked added to or subtracted from the starting date. Note that the results will differ between adding or subtracting 1 year or 1 month versus adding or subtracting 365 days or 30 days due to effects of daylight savings time, leap years, and calendar months having different number of days.

Date result: This is the calculated date and time after adding or subtracting the entered date and time units. Note that years and months are added or subtracted first, and then the weeks, days, hours, minutes, and seconds are added or subtracted after that.

[ Return to Top of Calculator ] [ Return to Top of Page ] Calcy pointing up

> > Date Time Calculator

+1 Page Site

Protected by Copyscape Online Plagiarism Detection
Calcy with money image
Top Ten Home
Money Calculators

Follow me on any of the social media sites below and be among the first to get a sneak peek at the newest and coolest calculators that are being added or updated each month.

Monthly What's New Email Update!

Who knows if I will show up in your next search. These monthly updates will insure you'll always know what I've been up to and where you can find me!

Terms, Privacy, and Consent * (all)
Online Pocket Calc