what are you looking to do? analog? digital? how many "increments"? hours & minutes or include seconds?
if digital, I have created two fields with hours and minutes and just used custom value lists. (this for 24 time or include am/pm toggle). client specifies 10 min increments, 15 minute increments or 1 minute increments.
keep in mind that it is generally faster to just type the time than "select" from list. But do what ever the client wants.