This is my probablem:

I have two separate data sets; one is a column of temperature data collected every 10 minutes (interval data) and the other a column of event data (which can be thought of as a random time), which records time when a window is opened or closed.
I want to sort the event data into a new column so that the time of its occurance will fall between the appropriate 10 minute interval eg event time 08:41:07 to fall between interval time 08:40:00 and 08:50:00. I am not quite sure what to do with multiple events between one 10 minute interval!

Example data...

28/07/2010 08:00:00 08:41:07
28/07/2010 08:10:00 08:46:38
28/07/2010 08:20:00 09:02:29
28/07/2010 08:30:00 09:10:45
28/07/2010 08:40:00 09:12:01
28/07/2010 08:50:00 09:17:38
28/07/2010 09:00:00 09:18:13
28/07/2010 09:10:00 09:19:06
28/07/2010 09:20:00 09:22:18
28/07/2010 09:30:00 09:25:08
28/07/2010 09:40:00 09:25:49
28/07/2010 09:50:00 09:26:02
28/07/2010 10:00:00 09:39:44