Try this:

=--ISNUMBER(MATCH(B1,A$1:A$10000,0))

Biff

"Ashley" wrote in message
...
Hi
I have a huge dataset, 10,000+ rows many times over, of date + hour.
(i.e. 7/1/2004 16:00)
The point of my data is that there is not a value for each consecutive
date
+ time, some are missing. I need to format my data (for a statistical
analysis program) so that one column shows every possible date + hour
comnbination for a 2-year period, and another column shows a "1" or "0"
for
whether or not that date exists in my original dataset or not,
respectively.
For example, my data looks like this:
7/1/2004 1:00
7/1/2004 2:00
7/1/2004 4:00
7/1/2004 5:00
And I want it look like this:
7/1/2004 1:00 1
7/1/2004 2:00 1
7/1/2004 3:00 0
7/1/2004 4:00 1
7/1/2004 5:00 1

It seems like VLOOKUP is the answer, but I can't get it to work. Am I on
the
right track, but maybe have a formatting problem?

Thanks for considering!!
Ashley