I should first note that unix file systems do not have creation times. Instead, there are access, modify, and change times.
To archive everything in directory 'example' that has not been modified since the start of 2009:
touch -d "1 Jan 2009" date-mark
tar cf subset.tar `find example -maxdepth 1 \! -newer date-mark`
The '-maxdepth' parameter prevents the 'find' command from recursing through the subdirectories, and the '\! -newer' looks for anything with a modification date older than the date-mark file. And those are backquotes around the find command.