I need to know how I can create an IF function where it will look at a cell with a time in it (e.g. 00:01:24) and determine if it is less than 20 minutes.

If it is I simply want a 1 to display in my target cell otherwise to remain blank.

Please can someone help me? I know how to do it with normal numbers but with a time format it is confusing me!! arrrgh

Many thanks!