Sometimes, we want to count a certain number of weekdays between two dates. If we want to count workdays, we need to use the NETWORKDAYS function. But, if we want to count the number of, let’s say Fridays, we have to use the NETWORKDAYS.INTL function. We start with the start date, finish with the end day, and then we modify weekends. In the Excel help description, we can see that we can change working days and days off using a text string of 1s and 0s, where 1 means a day off and 0 means a working day. So, Monday, Tuesday, Wednesday, Thursday are 1, Friday is 0, Saturday and Sunday are 1 (Fig. 1).
=NETWORKDAYS.INTL(A2,B2,“1111011”)

Here, we have the number of Fridays between two dates. It’s important that the function also considers the start date and the end date in its calculations (Fig. 2).

The NETWORKDAYS.INTL function can also work with holidays. Now, only Friday holidays are important for us, so let’s select the cell and press the F4 key to lock it (Fig. 4).
=NETWORKDAYS.INTL(A2,B2,1111011”,$F$3:$F#4)

And we have our results (Fig. 4).

Summing up, 0 means a working day, and 1 means a day off in the seven-number text string. If we write 0 also in the fourth place, it means that Thursday and Friday are working days (Fig. 5).
=NETWORKDAYS.INTL(A2,B2,1110011”,$F$3:$F#4)

As we can see, this small change modified our results once again (Fig. 6).
