sometimes, the start time will cross midnight

But the dates you've used are on three different days! change the last date to the 9th and you get a very reasonable average of 1:00.

use Date::Calc qw(Date_to_Time);
use POSIX;

my $time1 = Date_to_Time(2007,8,8,23,00,0);
my $time2 = Date_to_Time(2007,8,9,03,00,0);
my $time3 = Date_to_Time(2007,8,9,01,00,0);

print "$time1\t$time2\t$time3\n";

my $avg = sprintf "%0.0f", (($time1+$time2+$time3)/3);
print "$avg\n";

print strftime "%H:%M:%S\n", gmtime($avg);
__END__
1186614000      1186628400      1186621200
1186621200
01:00:00
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