What do you want to do that is different from this:
https://www.ebay.com/itm/HONEYWELL-HOBBS-169635-ELECTROMECHANICAL-12-60-VDC-BOAT-HOUR-METER-/192325910622 ?
Are you logging to SD card or a PC or do you just want to display the time the machine has been running. Do you need a resettable counter or must the time log be permanent?