my $_timestamp1 = '1189669351';
my $_timestamp2 = '1189355751';

printf "rounded: %.0f\n",($_timestamp1 - $_timestamp2) / 86400;
print "truncated: ",int( ($_timestamp1 - $_timestamp2) / 86400),"\n";
print "float: ",(($_timestamp1 - $_timestamp2) / 86400),"\n";
__END__
rounded: 4
truncated: 3
float: 3.62962962962963