Current date in the file name

Question

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.

Answer 1

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

Answer 2

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%
2009-06-01

theory » echo %time%
16:30:41,46

theory » echo %time::=%
163052,17

theory » echo %time::=,%
16,30,58,68

theory » echo backup-%date%-%time::=-%.zip
backup-2009-06-01-16-31-18,82.zip

Answer 3

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

Answer 4

I know the question wasn't about Unix, but for completeness, here's how to do it in bash:

% cp somefile.txt somefile-$(date +%Y%m%d-%H%M).txt