My Weekly Browsing Schedule stores the data in a folder called “Chrome” in your Firefox Profile folder.
You can easily find the files for My Weekly Browsing Schedule in the “Chrome” folder as they all end in: _lks4472.txt. Your schedule is saved in a file named schedules_lks4472.txt. You may also see files with the name schedules_0_lks4472.txt … schedules_6_lks4472.txt – these are backup files in case you accidentally delete your schedule file or your schedule file becomes corrupted.
If you want to copy your schedule across to a another computer, My Weekly Browsing Schedule shows you which file to copy: schedules_lks4472.txt. The location of the file (schedules_lks4472.txt) is shown at the bottom of the Options screen.
Your Firefox Profile folder can be found by following the instructions here: http://support.mozilla.com/en-US/kb/Profiles
I would suggest that you backup your Firefox Profile on a regular basis. There is a recommended Firefox Extension that will do this for you if you wish to: https://addons.mozilla.org/en-US/firefox/addon/febe/