use:

=IF(timevaltime(8,0,0),"yes","no")

where 'timeval' is the value that you are examining (e.g. A1 for the value
in column A1). In this example it is saying if the amount of time is 8
hours then set the value to "yes", else set it to "no". You can cause excel
to start a wizard for you by typing in the '=', then going to the dropdown
list that's at the far left just above the column indicators (A,B,...). That
dropdown will show you a list of functions. By clicking on a function name
excel will start a wizard that will walk you through the function parameters.

"Senaka Excel" wrote:

give example?
if in B2 cell having a time format how to identify it by using IF function?
to calculate overtime hours and minutes.
=(ifB20900,"yes","no")