Not using property setters in setDate and setTime

Setting a full date in multiple steps can lead to the wrong results when setting a date falling in a "daylight saving timezone". It is also slower to use magic setters without an actual good reason.
Merge branch 'patch-1' of https://github.com/lorenzo/Carbon
Merge pull request #6 from dereuromark/master-property

Not using property setters in setDate and setTime