With Time Calculator, you can add or subtract a number of years, months, days, hours, minutes, or seconds (decimal supported) to or from a date / time value:

You can also find out the difference between two date/time:

According to the definition of the Gregorian calendar, the following assumptions are made in this application:

• 1 Year = 365.25 days
• 1 Month = 30.436875 days
• 1 Week = 7 days
• 1 Day = 24 hours
• 1 Business Day = A day in between Monday and Friday inclusive, except local public holidays.
• 1 Hour = 60 Minutes
• 1 Minute = 60 Seconds
• Earliest date supported: January 2, 4713 B.C.
• Earliest Selectable Date: 0001/01/01 00:00:00
• Latest Selectable Date: 2099/12/31 23:59:59
• Largest Plus/Minus Value: 99999
• A.D. 2012 - 2012 years = 1 B.C., as there is no Year 0 by definition

Notice: Calculation results of this application are for reference purpose only; their accuracy is not guaranteed.