Good day,

I have every half hour of every day for three years in Column A (eg 1/01/2009 0:30, through to today 07/07/2013 10:00), and numerical data in column B.

I need to create four time periods in four different columns (D-G):
12.00am - 6:00am (column D)
6:00am - 12:00pm (column E)
12:00pm - 8:00pm (column F)
8:00pm - 12:00am (column G)

In those columns, if the time in column A, falls within the time period listed above (e.g. the date is 03/04/2009 4:00am, therefore falls within the time period in Column D), then I need to return all of the data points listed in the column for that time period. Every half hour of every day for 3 + years equates to 79,000 data points across those four columns.

I just cant get it right. Would appreciate anyones assistance. I have some very short deadlines on a work project.

Cheers

Tim