I have a table containing 3000 data points of measurements which were
automatically recorded every 20 minutes. They are arranged in two columns:
date time and measurement, e.g.:
Column A B
31/05/2007 08:00 2.35
31/05/2007 08:20 2.34
31/05/2007 08:40 2.44
31/05/2007 09:00 2.33
31/05/2007 09:20 2.41
etc
How can I filter these to only see the data recorded every hour on the hour?
I have tried playing around with AutoFilter etc which only produced the
first line of the data, and I can find no help anywhere.
All replies in easy language please.

Many thanks

Zoe