Subtract Length from Modification Date

Support
1

Looking for quick help.
I want to subtract Length of some m4a files from their Modification Date to obtain Creation Date. This can be done with exiftool (by subtracting Length total seconds from Modification Date seconds) but I've made a long Action Group in Mp3tag and want to done everything within it.

Example, one file has following Modification Date and Length:

08/11/2020 12:41:39 pm (%_file_mod_datetime%) and the length of this file is 01:22:51 which equals to 4971 seconds (%_length_seconds%).

How do you minus those seconds from that date.

I just don't know how to do it within Mp3tag. Help please!

2

See the help on arithmatic scripting functions

But once you have done the calculation - what are you going to do with it? MP3tag does not modify the file dates.

3

I didn't know Mp3tag wasn't able to change dates. How did I miss that :smile: