how to find files less than a day old?

[Brian John]

Hello,
I'm trying to write a script to concatenate a bunch of files.  Basically I
want to grab a bunch of files out of a directory that are less than an
hour or so old and put them in one file.

This is what I am using so far:

find . -mtime -1 -type f | xargs cat > temp.txt

However, this only grabs files that are less than a day old, so I get some
files returned that I don't want.  I tried using -0.5 instead of -1 and it
didn't work.  How can I accomplish this?

Thanks

/Brian