Work (business) days calculations with C#

If you think it’s a decent solution vote for it! :)

 

Work days between 2 dates:

public static double GetBusinessDays(DateTime startD, DateTime endD)

{

double calcBusinessDays =

1 + ((endD-startD).TotalDays * 5 –

(startD.DayOfWeek-endD.DayOfWeek) * 2) / 7;

if (endD.DayOfWeek == DayOfWeek.Saturday) calcBusinessDays –;

if (startD.DayOfWeek == DayOfWeek.Sunday) calcBusinessDays –;

return calcBusinessDays;

}

 

Note 1: Some changes are made to comply with the changes made by admins of StackOverflow.com site. They did removed unnecessary cast to int.

Note 2: Another useful input from the same site: Just to remark, with the ‘1+’ it assumes start of first day until end of last day, without the ‘1+’ it assumes end of first day until end of last day. Took me a while to figure that out, since I was assuming start of first day until start of last day, which made more sense to me. – Jeffry van de Vuurst Oct 23 ’15 at 9:21

Note 3: The code is relying on the fact that by default in C# (int)DayOfWeek.Saturday is 6 and (int)DayOfWeek.Sunday is 0. This option might be different in your region so the code should be refactored accordingly. Looks like both “ifs” could be removed if Monday would be  0 (if week starts Monday). Need to be tested though.

Add work days to a start date:

DateTime startD = new DateTime(2000, 5, 28);

double businessDays = 2300;

int DoW = (int)startD.DayOfWeek;

double temp = businessDays + DoW + 1;

if (DoW != 0) temp –;

DateTime calcendD = startD.AddDays(

Math.Floor(temp / 5)*2-DoW + temp

– 2* Convert.ToInt32(temp % 5 == 0)) ;