This timer would be really awesome if you could set the units measured as milliseconds, seconds, hours, days, weeks, and combinations too. 4 days+4 hours for instance of a 100 hour service interval. I always use run timers on all equipment for the purpose of determining the equipment life, service interval etc. This would make it really easy to do with a single instruction. Machine I am working on has 3 servos, 16 spindles and 6 tools to track run time on.