exiftool:tldr:53ce2

This command uses the ExifTool software to modify the value of the "DateTimeOriginal" tag in the metadata of an image file. The command is as follows:

exiftool -DateTimeOriginal-=1.5 -overwrite_original

Here's a breakdown of what each part of the command does:

• "exiftool": This is the command to invoke the ExifTool software, which is a powerful tool used for reading, writing, and manipulating metadata in various file formats, including image files.

• "-DateTimeOriginal": This specifies the tag name within the metadata that we want to modify. In this case, it is the "DateTimeOriginal" tag, which typically represents the date and time the photo was taken.

• "-=1.5": The "-=" operator is used to subtract a value from the existing value of the tag. In this case, we are subtracting 1.5 from the current value of the "DateTimeOriginal" tag.

• "-overwrite_original": This option allows ExifTool to modify the original file, replacing it with the updated version. Without this option, a new file with "_original" appended to the original filename would be created, leaving the original file intact.

The purpose of this command is to shift the original date and time of the photo by subtracting 1.5 units from it. The unit of measurement for time depends on the specific format used in the "DateTimeOriginal" tag. For example, it could be in seconds, minutes, or hours.