Use VLOOKUP()

Your data looks like it is sorted by date and time already. VLOOKUP will
find the very first record of any date (in your case, the first day of each
month)
--
Gary's Student


"pex" wrote:

I have a table with a new value every hour:

Date Time Value

2005-01-01 00:00:00 1
2005-01-01 01:00:01 4
. . .
. . .
. . .
2005-01-02 00:00:00 34
. . .
. . .
2005-02-01 00:00:00 145

etc..

The only rows i need from this table is the first value every month (date,
time and value), but I how do I do?

(timestamp can differ a couple of seconds every our)