Classic ASP number of weekdays between dates

Question

Is there any way in Classic ASP VBScript to get the number of weekdays between 2 dates? Obviously, we have the DateDiff() function but this will pull back the total

Answer 1

You're right, DateDiff() doesn't cover this but it can be used in conjunction with WeekDay() to work out if a Day falls on a weekend.

By using DateDiff() to get the number of days we can then use a For loop to step through the days using DateAdd() to increment the day as we go and check whether the incremented date value is a particular WeekDay(). We can then decide based on this outcome whether to increment a counter that is storing our resulting number of weekdays.

Below is an example of how you would do this, the main logic has been encapsulated in a Function that you could include in a #include script file to use in multiple pages.

<%
Function DateDiffWeekDays(d1, d2)
    Dim dy: dy = 0
    Dim dys: dys = DateDiff("d", d1, d2)
    Dim isWeekDay: isWeekDay = False
    Dim wkd
    Dim wd: wd = 0

    For dy = 0 To dys
        wkd = Weekday(DateAdd("d", dy, d1))
        isWeekDay = Not (wkd = vbSunday Or wkd = vbSaturday)
        If isWeekDay Then wd = wd + 1
    Next
    DateDiffWeekDays = wd
End Function

'Example of how to call the function and output to the page
Call Response.Write(DateDiffWeekDays(Date(), CDate("12 Nov 2018")))
%>

Output:

16

This is just a quick example and doesn't cover every possible usage case, the idea is it gives you a starting point that you can work from and improve.