If you are able to open cash drawer during normal operation then auto open when starts/ends is easy.
First you have to create a printer template that contains code <DRAWER> or <XCT bla bla> to open the drawer. You can put it under header or footer.
Second you create print job that will send the code to the drawer (e.g. through a printer that connects with the drawer)
Third you assign the print job to a terminal.
Forth you create an action to execute the print job.
Fifth you create a rule to execute the action when work period starts and another one when the work period ends.
Hope this one works for you because I use it to check all 4 printers in my restaurant when work period starts and ends.