I have cells with dates in this format: DD/MM/YYYY 00:00:00 and I want to add 3 hours because I'm in a different GMT zone.

Is possible to use dates in a formula?

Something like: 30/12/2012 22:15:00 should become: 31/12/2012 01:15:00

4 Answers 4


All date/time values in spreadsheets are internally handled as floating point values. To add 3 hours to a date/time just add (3/24) to the original date/time.


This also works in MS Excel.

  • Thanks, I did't knew that... One more thing, I'm using importrange to brin that dates... And I can't figure out how to do it with that... =importrange("xxxMyKeyxxx";"Archive!E2:E") ... Where should I add "+(3/24)"? Thanks again
    – Santiago
    Jul 11, 2012 at 22:14
  • Awesome answer! And to add +15 minutes.... (15/1440) Aug 11, 2017 at 22:55
  • this worked. The other answer did not Feb 15, 2023 at 4:46

See also: Convert a date in Google Spreadsheet?


Adds 3 'Hours', 0 'Minutes', 0 'Seconds' to the date/time value of A1

Additionally if only you use the main sheet you can go into the sheet settings and change it's timezone accordingly.


I do this for my work schedule to track different projects:

Three columns A B C where column A is text, B is hours, C is minutes.

In Time 8:00 AM is B2

WLI     3   15

ADMS2   2    0

O&M     2   30

Break   0   15

Total   7   45

Out Time 3:45 PM

Total: =SUM(B3:B6) for hours, =SUM(C3:C6) for minutes

Out Time: =SUM(B2,(B7+C7/60)/24)

  • There is help available for the editor. Just click the question mark to the upper right of the editor. In this case, though, with tabular data, code format works reasonably well.
    – ale
    Jan 7, 2014 at 16:46

3 hours are equal to the value of 0.125, therefore shortest formula would be:


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