Goal of this project is, creating a calculator that can handle all date and time operations that a user may need.
You can operate with milliseconds as months, years or dates.
Examples:
2013-11-25 + 3d => 2013-11-28
2013-11-25 - 2013-10-20 => 36d 1h
5h + 6h => 11h
1382220000t => 2013-10-20
Joda-time based utility Java class that allows calculation related to downtimes. You set a list of downtimes (date-time intervals), and the calculator will give you the ending date-time of a duration, and uptime between two points in time, too.