I want to calculate the number of days worked on a project in a rolling 4
month calendar. Working Days are Mon-Thu. My sheet looks like this:

Jobname TotalDays StartDate EndDate DaysMo1 DaysMo2 DaysMo3 DaysMo4
Foo 3 3-22-10 3-25-10 3 0
0 0
Goo 25 4-2-10 5-17-10 0 17 8
0

I have used Workday to calculate my enddate but I'm having difficulty
calculating the proper month bins to put the days in. Since the calendar
rolls forward ewach month I need to consider that a job started before Mo1 or
in Mo1 or in Mo2 or in Mo4 or it'sw beyond the planning horizon. Anyone
solved this before?

Thanks for any guidence