When we plan a job/service or similar we have contract/agreements/estimations (or similar) where we state the work needed in Hours to perform this job.

To have duration display as e.g.3,75 days is utterly confusing, someone looking at that would think this job would take almost 4 days, but if you consider that the number behind here is 90 Hours the actual job will take about 7-12 days (depending if you work 8 or 12 hours per day)

We are using the duration fields on service tasks and on work order

msdyn_totalestimatedduration and msdyn_estimatedduration

Kindly make these display fields system or user configurable so we can set these fields to only display hours

Found this similar Idea but here they focus on bill duration.

https://experience.dynamics.com/ideas/idea/?ideaid=97fac98c-6fc0-ea11-bf21-0003ff68a0e7