I am having difficulty devising a formula that works. What I need is a
formula that will round time up or down to the nearest quarter hour. For
example, if a person were to enter 4:06 PM I need a formula that would
calculate 4:00 PM; or if they enter 4:11 PM it would calculate 4:15 PM.

Also I have another question, what is the difference in the cell format
settings of h:mm and [h]:mm. I am using the first (h:mm) for doing
calculations with times.

I appreciate any assistance that anybody can offer, if you need more info
please let me know.

Thank you,