HI Mohd Salman,
What is the business logic that you wanted to have to calculate Working hours in your application. 
 Can you explain the use case more in detail.

Dear Mohd,

That is a business-dependent question, I think. E.g. when working in the Dutch health-care system, 36 hours per week is the maximum work time for 1fte. Moreover, shifts can occur any time in the week/day. Contrastingly, in Dutch education, working time is generally between 08:00 and 17:00, but there are many exceptions, e.g. when having parent-teacher assembly (in the evenings). Concluding, it completely depends on your working-time business definition.

That being said, it would be possible to create a model that would store this information: consider a Workday entity, that would have two attributes: StartTime and EndTime. Perhaps add attributes such as IsNationalHoliday, in order to prevent bookings on that day, or convenience attributes such as FriendlyName (e.g. “Wednesday”) or DateString (“1/5/16”). Subsequently, it would be possible to retrieve this Workday entity for validation purposes, or for outlining booking availability.  

Hope this helps; if it does, please mark as correct ;-)

Best regards,

Wouter Penris