I've got different results - there is a difference of 5 hours from yours. I'm trying to figure out why.

perl -MDateTime -e ' print DateTime->new(year=>1970)->epoch, $/ '
0

perl -MDateTime -e ' print DateTime->new(year=>1948,month=>12,day=>25)
+->epoch, $/ '
-663292800

perl -e 'print +( 663292800 - 663274800 )/3600 , $/ '
5
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