"MAXIF" formula?

Hi Guys,

Example attached.

I have a grid of data

Column A - D365 days
Row 1 - Half hourly times for the day (columns B - AW)

On sheet 2 I am looking for a formla which whill Return the MAXIMUM Value which occurs for each month.

I was hoping to find some kind of MAXIF formula but I don't think one exists.

Thanks for your help

F