true
if the two given datetimes are exactly the same, otherwise returns false
.DATETIME_IS_SAME("2011-10-10T12:13:14Z", "2011-10-09T12:13:14Z")
false
DATETIME_IS_SAME("2011-10-10T12:13:14Z", "2011-10-10T12:13:14Z")
true
DATETIME_IS_SAME("2011-10-10T12:13:14Z", "2011-10-09T12:13:14Z", "year")
true