Reports: Time Accounting By Technician

I believe this would be a great option for a Company including for my self to track not only what tickets a technician or agent has already worked on (Already a Feature) but How many Hours the technician has spent on a ticket so our Clients can be billed for time and our Technicians can have their daily hours quota tracked as some must mean 6.0 Billed ours at .25 increments while others are required a 5.5 total hours. I am confident this feature which is available in some other ticket systems that are major players in the MSP world and corp world (i.e. ServiceNow) will arrive to Zammad soon.

Any suggestions to get this via API will help.