tor-browser-build/projects/firefox/get-moz-build-date

#!/usr/bin/perl -w
# Generate a MOZ_BUILD_DATE based on firefox version number

use strict;

die "wrong number of arguments" unless @ARGV == 2;
my ($year, $version) = @ARGV;
$version =~ s/\D+$//;
my @v = split(/[\.ab]/, $version);
push @v, '0' if @v < 4;
push @v, '0' if @v < 4;
my $day_of_month = int(($v[0] - 45) / 5);
my $date = 101010101 + $year * 10000000000 + $day_of_month * 1000000
           + $v[1] * 10000 + $v[2] * 100 + $v[3];
$date += 100000000 unless $version =~ m/[ab]/;
print "export MOZ_BUILD_DATE=$date\n";