Whoa! Evil! cgi-lib.pl was a 'standard' some time ago, but the best thing to use is CGI.pm to do form processing, and an easy way to create HTML (amung other things). If you want, CGI.pm can be used in 'cgi-lib' mode so you shouldn't have to change your method calls. Read the documentation for CGI.pm to learn more about that.
Secondly you should really be using the strict pragma (use strict;) and -w. These will really help you learn how to be a better programmer, and you will get to learn about interesting things like scope!
Some people will disagree with me on this, but I tend to like getting the date using POSIX.pm. Look at the documentation for POSIX, and the strftime() method. Also look at the man page for strftime(3) to see formats. If you agree or not on this, it is still good to look at the module, since it can do quite a bit. Personally, I don't see the use of the text file saying what time the script began.
I don't think backticks should be used in CGIs. Although nothing is between them which is passed in from an untrusted source, it is better to use system() in a save manner, like:
Look at perlsec for safe uses of system()
open(OLDPAGE2, $startfile); $filesize = -s OLDPAGE; read(OLDPAGE2, $heading, $filesize); close(OLDPAGE2);
I'm not really sure why you are not just opening the file and reading it in. Why are you using read()?