exiftool:tldr:21bda

This command is using exiftool, a command-line tool used for reading, writing, and manipulating metadata within various file formats, particularly for image files.

The command is structured as follows:

exiftool: This is the name of the command being executed.

"-AllDates-=0:0:1 2:0:0": This is an argument passed to the exiftool command. It is instructing exiftool to modify the metadata related to the dates within the specified image files (in this case, files with the ".jpg" extension). The specific modification being made is to subtract the specified time duration from all date tags (such as date created, date modified, etc.). The time duration specified here is "0:0:1 2:0:0", which means subtract 1 day and 2 hours from the existing date.

-ext jpg: This is an additional argument specifying the file extension for the image files to be processed by exiftool. In this case, it is set to ".jpg", indicating that only files with the ".jpg" extension will be affected.

Overall, this command is telling exiftool to modify the date-related metadata in JPG files, subtracting 1 day and 2 hours from the existing dates.