Date scheduled jobs

[BrettRToomey]

Time of day support

Example:

//pseudocode
let morning = Date("08:00")
Jobs.shared.add(date: morning ) {
    print("Good morning!")
}

• [ ] Date support
• [ ] Unix timestamp support

[BrettRToomey]

Coming up with a date interface that isn't frustrating to use is going to take quite some time, so I'm going to push the release of this and #5 to 0.1.0