Change the DateDiff function so that it returns int instead or real and doesn't return factional numbers

Currently, the DateDiff function factors in the fraction of the whole when returning the differences between year, quarter, month, etc.   This can be confusing and hard to use when trying to calculate the differences between months as it will return 1.00001 or 12.999994 between months which have longer or shorter amounts of days in those months.   This makes comparisons using this function harder to use as you can't simply use integers for comparisons.  As an example you can't simply write a calculation to give me any data where the date differences is =>24 and <=36 months since some will be 23.99999 and some will be 36.99999.