Use conditional formatting.

In the cell that has the time (assumed to be A1 here), choose FormatConditional
Formatting...

Change Condition 1 to Formula is, enter the following formula

=AND(INT(A1/"00:30")*"00:30"<NOW()-TODAY(),INT(A1/"00:30")*"00:30"+"00:30"NOW()-TODAY())

Choose Format..., and whatever highlight you want, such as Pattern grey.

Copy the formatting as far down as needed.

--
Regards,
Fred


"Lorri" wrote in message
...
I have a spreadsheet that is utilized as a schedule for phone coverage. Each
cell is in half hour increments. I want to have the current time in one cell
that the rest of the cells reference in a formula to highlight the row that
fits the timeframe. How can I do this? Or is it even possible? Or is there
another appllication that might be better?