datetime stop derivations
datetime stop from start and length
symbol description unit variable name \(t_{e}\) datetime stop \(s\) since 2000-01-01 datetime_stop {time} \(t_{s}\) datetime start \(s\) since 2000-01-01 datetime_start {time} \(\Delta t\) time duration \(s\) datetime_length {time} \[t_{e} = t_{s} + \Delta t\]