number of Full Months between dates & partial Days calculation

[Silvio]

Hello, I need help in write 3 piece of code in VBA to calculate the following:
1. The number of full months between two dates
2. The number of days to the end of the same month if the start date is NOT
the 1st of the month
3. The number of days from the beginning of the End Date if the end date is
not the last day of the month
Example:
Start Date: 9/18/09
End Date: 12/15/09

Result:
Total of Full Month: 2 (only October and November are full between the two
dates above)
Start Days: 13 (Between 9/18/09 included to 9/30/09 included)
Ending Days: 15 (Between 12/1/09 to 12/15/09)

Thank you,
Silvio

 

[Douglas J. Steele]

The number of full months would be

DateDiff("m", StartDate, EndDate) - IIf(Day(EndDate) < Day(StartDate), 1, 0)

The number of days to the end of the month for the start date is

Day(DateSerial(Year(StartDate), Month(StartDate) + 1, 0) - Day(StartDate)

(depending on your definition, you may want to add 1 to that)

The number of days from the beginning of the month for the end date is

Day(EndDate)