Webmaster Tools » Date/Time Calculator
Calculate the time since or until a specified date, time difference between two dates or times, or add or subtract time interval.
What is Date/Time Calculator?
Our Date/Time Calculator is a free online tool that calculates dates and date intervals and allows:
- To explore the date/time properties - how much weeks, days, hours passed since the date/time or how much time left until it.
- To calculate the time difference between two dates.
- To add or substract time interval to a given date/time.
Any real-world examples?
- How long till Friday?
- How many days until Christmas Day?
- What is the last day of Oktoberfest?
- When is Labor Day in the US?
- How old is Elon Musk?
- How long ago did man first walk on the moon?
- How long until Chinese New Year 2023?
- How old is Internet?
- How long has 3G Been Around?
- How long did World War II last exactly?
- How many yeas did Queen Elizabeth II live?
How to use
To calculate the difference between two dates and/or times of day, enter a date and/or time into the fields above in almost any conventional date/time format.
The default time zone is UTC (Universal Coordinated Time, GMT).
This calculator can be used to add or subtract two time values. The first date can be left blank, which will be taken as "Now" by default. In the second field you can enter any date, time, or interval addition or substraction, for example "+180 days", "-6 month", "+38 weeks", "36 hours", etc.
Some usage cases our calculator is useful for:
- You know the start date and need to count how many days have passed since you received the bill or letter.
- You want to calculate the end date of validity of your vaccination certificate, prescription, etc. For example, you can easily calculate the expiration date of your EU Digital COVID Certificate adding the validity period of 270 days to your date of vaccination.
- You know the date of your departure and want to know that is the last date to buy tickets at the early bird price.
- You know the date of purchase and want to know how long the electric bulb/your phone/any other product lasted.
What datetime formats are supported?
The calculator can handle almost any date/time format, including:
- March 1 1994
- July 30, 2020 4:50
- 15 March 2022
- 2022-03-15 10:55
- 2022-03-15 10:55 pm
- 2022-03-15 10:55 pm UTC
- 2022-03-15 10:55 pm PST
- First sunday of May
- @1215282385 (prepend number with @ to be interpreted as a Unix Timestamp)