postiong date variable should run report only for that month

Hello all,

I have a report which should give detail transaction for that particular month when run at the end of the month. right now I am giving posting date as the variable as Day Interval and the user inputs the start and end date.

Is there any way we can make it that when it is run at the end of month it should take the value for 1st of month and final day of month?

Thanks,

KM