Crystal Reports Previous Month Calculation

I needed to get a report to run via Business Objects scheduler which would return data for the previous full month. So a Report run on 1st Feb, would return all data within a date range of 1st Jan – 31st Jan.

But the report would also need to be able to run on specific dates if the user required.

Step 1 – Create “Previous Month” Parameter”.

So I created a parameter which was a simple Y/N drop down. If “Y” was selected it would return the data for the previous Month.

{?CurMonth}

If N was selected, the report would use a Start Month and End Month Parameter values to return the required data.

Step 2. – Create Forumla to work out Previous Full Month Start/End Date 

Create forumla @strFDMonth
This will calculate the First Day of the Previous Full Month.

minimum(Lastfullmonth)

Create forumla @strLDMonth
This will calculate the LadDay of the Previous Full Month.

maximum(Lastfullmonth)

Step 3 – Enter Selection Criteria

If {?CurMonth} = ‘Y’ Then
{DATE_FIELD} >= {@StrFDMonth} and {DATE_FIELD}} <= {@StrLDMonth}
else
{DATE_FIELD}} >= cdate({?STARTDATE}) and {DATE_FIELD} <= cdate({?ENDDATE})