I have a column populated with dates. I want a cell in another worksheet to
count how many of the dates in the aforementioned column are less than a user
defined date. I.e. I want the cell to display how many dates fall before 15th
August. I am unsure as to how to write this correctly. Currently I have:

=COUNTIF('Sheet1'!AH16:AH97, "<15/08/2005")

Is this correct?

What would SUMIF do in contrast?