Use the LAST_DAY function. You can look it up in the SQL Reference manual. Paul Baumgartel CREDIT SUISSE Information Technology Prime Services Databases Americas One Madison Avenue New York, NY 10010 USA Phone 212.538.1143 paul.baumgartel@xxxxxxxxxxxxxxxxx www.credit-suisse.com ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Rick Ricky Sent: Tuesday, May 13, 2008 1:45 PM To: oracle-l@xxxxxxxxxxxxx Subject: help with a monthly rollup I need to rollup data by month. There are a couple ways to do this. I have a date field. So I can rollup with a to_char(mydate,'YYYYMM') this requires a where clause as followings where to_char(mydate,'YYYYMM') = pSomeMonth; This means I need a function based index to support this. We have alot of data, so where possible, I want to avoid adding more indexes. Is there a way to calculate what the last day of the month is? so I can use a between as follows where myDate between to_date(01-MON-YYYY') and to_date(LASTDAYOFMONTH-MON-YYYY') Since the last day of the month can be 28,29,30,31 ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ==============================================================================