Add a column that returns the day (e.g. =Day(yourdatetimecell)) then SumIf
based on that column. You can, obviously, hide that column.

"RedDixieCup" wrote:

I have two colums of data, the first is a time date stamp (mm/dd/yyy hh:mm)
and the second is a rainfall total for each entry (0.00). I need to get a
daily rainfall total.