The macOS Migration Assistant in Applications/Utilities will transfer all your data to another machine. Migration Assistant Manual
If you want to migrate the data manually, find the correct folder below and copy it to the same place on the new mac.
Starting with GrandTotal 6 the .grandtotal files are saved in user selected location. If you click on the window title while holding down the ⌘ key, you can display the location in the Finder.
For other applications and older versions of GrandTotal, either download and launch this Application or look for it manually.
|GrandTotal 6||User picked location|
|GrandTotal 3, 4 & 5||~/Library/Application Support/com.mediaatelier.GrandTotal3|
|GrandTotal 1 & 2||~/Library/Application Support/GrandTotal|
In case your hard disk or SSD should have a failure, you can restore the data folder using Time Machine or your backup tool. The application (GrandTotal, Timings etc.) needs to be closed first. Time Machine Manual