I have scheduled backup script that makes the database dump. How can I add the date timestamp to the file name?

I am talking about Windows and CMD.

5 Answers 5


In the command prompt and batch files, you can use %date% and %time% to return the date and time respectively. Date works fine, but the time value returned contains colons, which are illegal for use in filenames, but there is a way to remove those.

Use something like:

COPY file.txt file_%time:~0,2%%time:~3,2%%time:~6,2%_%date:~-10,2%%date:~-7,2%%date:~-4,4%.txt

This will produce a filename such as file_172215_01062009.txt

Update: The comments below have interesting twists on this command as well as some potential problems you can avoid.

  • 4
    Great little tip. BTW, if you do it the other way around, that is: "file_20090601_172215", you will see the files in the correct order in an alphabetic list.
    – TonJ
    Commented Jun 1, 2009 at 13:00
  • 6
    You can also use %time::=% to remove the colons. Commented Jun 1, 2009 at 13:33
  • 5
    I'd say that date substring-ing would break as soon as the system locale differs from when the script was tested? It could even work for the testing user and break as the script runner because of different date display formats set... Commented Jun 1, 2009 at 18:17
  • 5
    Beware hours 0 - 9! CMD sets the first character of the hour to <SPACE>, rather than 0. The COPY command above is going to have problems if you don't enclose the destination filename in quotes. Commented Jun 1, 2009 at 20:09
  • 5
    Note that %DATE% and %TIME% are locale-aware! It means that on a European machine, you get DD.MM.YYYY. Arrgh.
    – Pekka
    Commented Jan 26, 2011 at 20:36

Use the %DATE% and/or %TIME environment variables, optionally substituting the characters that are not allowed in filenames, using %name:from=to% (%TIME::=% would remove all colons).

theory » echo %date%

theory » echo %time%

theory » echo %time::=%

theory » echo %time::=,%

theory » echo backup-%date%-%time::=-%.zip
  • 3
    wow, never know about the :x=y trick. that's really cool. Commented Jun 1, 2009 at 21:37
  • 1
    +1 for the := trick, iv'e been in this game since MS-Dos 1 and that's the first time Iv'e seen that one. Would be even better if you could change multiple chars too!! :-)
    – shawty
    Commented Sep 17, 2018 at 12:02
  • Well, it was only added to Cmd.exe in the Windows NT series... And if you want to perform multiple changes, just have a chain of set tmp=%tmp:x=y% etc. Commented Sep 17, 2018 at 12:12
  • 3
    The content of %DATE% (number of fileds, content and ordering) are locale specific.
    – symcbean
    Commented Apr 4, 2019 at 13:26

The only reliable way to get appropriate date whatever regional setting are, is the solution from foxidrive @ https://stackoverflow.com/questions/11037831/filename-timestamp-in-windows-cmd-batch-script

@echo off
for /f "tokens=2 delims==" %%a in ('wmic OS Get localdatetime /value') do set "dt=%%a"
set "YY=%dt:~2,2%" & set "YYYY=%dt:~0,4%" & set "MM=%dt:~4,2%" & set "DD=%dt:~6,2%"
set "HH=%dt:~8,2%" & set "Min=%dt:~10,2%" & set "Sec=%dt:~12,2%"

set "datestamp=%YYYY%%MM%%DD%" & set "timestamp=%HH%%Min%%Sec%"
set "fullstamp=%YYYY%-%MM%-%DD%_%HH%-%Min%-%Sec%"
echo datestamp: "%datestamp%"
echo timestamp: "%timestamp%"
echo fullstamp: "%fullstamp%"

Use %DATE% variable in the filename.

There is a %TIME% variable as well, but it contains characters not allowed in a file name.

Here is an example of writing a line of text into a new file, where the file created has a date and time in its name.

echo "testfile" >> backup-%DATE%.txt

Use the %date% and %time% variables, and you can use For /f command to parse the tokens delimited by / or locale-specific format to change formats.

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