A first step is to use a correct value for the month, which should be in the range from 0 to 11.

The problem with years > 138 is that timestamps for the year 2038 don't fit into a 32 bit integer anymore.

This is fixed in current bleadperl. Maybe also some CPAN modules do correct date manipulation beyond 2038, maybe you should try some of them.

Update: I'm a bit curious - what do you need post-2038 dates for?

Second update: If you want to play with it a bit more I recommend POSIX::mktime:

# start of epoch
$ perl -MPOSIX=mktime -wle 'print mktime(0,0,1,1,0,70);'
0 but true

# before epoch
$ perl -MPOSIX=mktime -wle 'print mktime(0,0,1,1,0,60);'
-315619200

# "normal" dates:
perl -MPOSIX=mktime -wle 'print mktime(0,0,1,1,0,100);'
946684800

# how close do we get to 2**32-1 ?
$ perl -MPOSIX=mktime -wle 'print mktime(7,14,4,19,0,138);'
2147483647
$ perl -MPOSIX=mktime -wle 'print mktime(8,14,4,19,0,138);'
Use of uninitialized value in print at -e line 1.
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