setDate(333333, 1, 1); $end->setTime(16, 18, 02); $start = new DateTime; $start->setDate(-333333, 1, 1); $start->setTime(16, 18, 02); examine_diff($end, $start, 'P+666666Y0M0DT0H0M0S', 243494757); echo "test_massive_negative: "; $end = new DateTime; $end->setDate(-333333, 1, 1); $end->setTime(16, 18, 02); $start = new DateTime; $start->setDate(333333, 1, 1); $start->setTime(16, 18, 02); examine_diff($end, $start, 'P-666666Y0M0DT0H0M0S', 243494757);