Determining If a Date and Time is within Working Hours

Ken has a date and time stored in cell C3. He needs a formula to determine if this date and time is within normal working hours (8 am to 5 pm, Monday through Friday). Ken can easily check the time, but can't figure out a way to check whether it is on a workday.

There are a multitude of formulas you could come up with to solve this situation. The key components of any formula are that you determine if the date is within the range of Monday through Friday (which Ken says he knows how to do) and determine if the time is in the range of 8 am to 5 pm. Once you determine these two facts, you can use the AND function to determine an overall "true" or "false" condition.

As an example, you could use the following formula to determine if the date is in the range of Monday through Friday:

=WEEKDAY(C3, 2) < 6

This returns either True or False and works because the second parameter of the WEEKDAY function, when set to 2, indicates that WEEKDAY return a value of 1 through 7 where 1=Monday and 7=Sunday. Thus, WEEKDAY would return 1, 2, 3, 4, or 5 for the range of Monday through Friday.

For the time portion of the formula, you could use the the HOUR function, in this manner:

=HOUR(C3) >= 8

This returns True or False depending on whether the hour is greater than or equal to 8:00 am. You can test, similarly, if the hour is before 5:00 pm in this way:

=HOUR(C3) <= 17

With these three tests figured out, you can combine them all using the AND function:

=AND(WEEKDAY(C3, 2) < 6, HOUR(C3) >= 8, HOUR(C3) <= 17)

Since the HOUR function returns an integer value (0 through 23), you could shorten the formula even further in this manner:

=AND(WEEKDAY(C3, 2) < 6, HOUR(C3) > 7, HOUR(C3) < 18)

If all three conditions are met, then the AND function returns True. Thus, you could wrap this formula inside of an IF statement, like this:

=IF(AND(WEEKDAY(C3, 2) < 6, HOUR(C3) > 7, HOUR(C3) < 18), "Working", "Non-Working")

This works great, unless you want to start taking holidays into account or your workweek is different than Monday through Friday. In that case, you only need to modify the first part of the formula; the part that uses the WEEKDAY function. My suggestion would be to rely, instead, on either the NETWORKDAYS or NETWORKDAYS.INTL functions. Rather than describe here how to use those functions, you'll want to refer to the ExcelTip entitled "Calculating Business Days."

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (4270) applies to Microsoft Excel 2007, 2010, 2013, and 2016.