I'm not aware of how you can do this without custom development. I mean you can do it with 3 fields I suppose, 1 to show current time (read only), 1 to show time to give, 1 to show who to give it to; then like 10 auto actions to deal with all this, but it's absolutely ugly and non-user friendly. Something like this really needs custom development as a new CB plugin. I suggest viewing our CB api documentation within the free downloads section as well as reviewing existing plugins for a starting point.