To add or subtract dates, treat them as regular numbers. Dates are in fact
stored as the number of days from 1/0/1900 (1/1/1900 is stored as 1). You
can check this by entering a date and then formating the cell as a number.
When you subtract a date from another date the result "looks" like a date,
but it is not. You need to change the cell format to a number after entering
the formula.

Example
A1-D1: various dates
I1-I3: various integers
E1: =(A1-B1) + (C1-D1)
F1: =IF(E16,IF(E110,IF(E131,I3*E1,I2*E1),E1*I1),E1)

F1 outputs:
E1 if E1<6
E1*I1 if 6<E1<10
E1*I2 if 10<E1<31
E1*I3 if E131

Be sure to format E1 and F1 as numbers after entering the formulas.

"Bryan J Bloom" wrote:

I need to subtract 2 different sets of dates to get a total amount of days.
Eg: (a-b)+(c-d) = e
I then need to take the total (e) and multiply by 3 different integers if
the total (e) is greater than 6 days,10 days and 31days.
This helps me keep track how long my company trucks are out of a Rail/Ship
Yard.
I can't seem to get the dates to subtract and get an integer(regular
number). and I'm dead lost on the greater than stuff.
Of course the boss drops this on me on my first day.
Any help or comments will come highly appreciated.
Thank you