One such minor enhancement that Google has introduced in Android 4.4 KitKat is the ability to dismiss upcoming alarms from the notification bar. A notification with the ability to dismiss an upcoming alarm will show up on the notification bar 2 hours before the alarm is ready to go off.
This new feature is a part of the new Clock application introduced in Android 4.4, rather than the OS itself.
I think you have to have clock version 3.0.0 (settings>apps>all>clock) for it