The following test checks if an existing milliseconds value gets preserved if a call to setHours(), setMinutes() or setSeconds() does not specify the milliseconds. See https://bugs.webkit.org/show_bug.cgi?id=3759 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS d.getMilliseconds() is 1 PASS d.getMilliseconds() is 1 PASS d.getMilliseconds() is 1 PASS d.getMilliseconds() is 1 PASS d.getMilliseconds() is 1 PASS d.getMilliseconds() is 1 PASS successfullyParsed is true TEST COMPLETE