How to read the duration value from GetTasks API

I use getTasksRequest to get the name, start, finish and duration. I get the duration value but I am not sure on how to read it:
An example on where I get stuck reading the duration:
“Name”: “Prepare project plan”,
“Start”: “2024-03-19T08:00:00”,
“Finish”: “2024-04-05T17:00:00”,
“Duration”: “4.16:00:00”
There are 18 calendar days between the two dates. I cannot understand what does the duration value returned means.

@leliofa ,

“4.16:00:00” is a TimeSpan representation (https://learn.microsoft.com/en-us/dotnet/standard/base-types/standard-timespan-format-strings#the-constant-c-format-specifier) of 112 hours.

The duration in project management software is usually measured in working hours / working days.
The duration between 19 March 08:00 and 05 April 2024 17:00 is 14 working days.
Usually each working day equals to 8 working hours.
Thus the duration of the task is 112 working hours.