How to find the files that are created in the last hour in unix
UNIX filesystems (generally) don't store creation times. Instead, there are only access time, (data) modification time, and (inode) change time.
That being said, find has -atime -mtime -ctime predicates:
$ man 1 find
...
-ctime n
The primary shall evaluate as true if the time of last change of
file status information subtracted from the initialization time,
divided by 86400 (with any remainder discarded), is n.
...
Thus find -ctime 0 finds everything for which the inode has changed (e.g. includes file creation, but also counts link count and permissions and filesize change) less than an hour ago.