Count Number of Partial/Full Weeks Between Dates

[Excel4444]

I am trying to count the number of occurring weeks between two dates, such as 1/4/2018 - 1/14/2018. This technically equals 11 days and "touches" 3 separates weeks, but I can't just count days and divide by 7. I would also need to do this for larger time periods such as 3/13/2012 - 7/25/2018 and I would encounter the same issue being that in march the 13 is a Wednesday and in June the 25th is a Monday.

So the data is basically a start date in column A and end date in column B

 

[jim may]

Is there a day of the week which is the official first day of the (7 day) week?

 

[Excel4444]

No.
Start and end dates can vary the entire work.

 

[jim may]

For your first example to yield 3 it does seem that a visual layout from Sunday to Saturday is involved and that is what should be considered.

 

[Excel4444]

Yes, a week is in this example sun-sat.

 

[Excel4444]

Any suggestions would be super helpful!