duration between two datetimes
(datetime start, datetime end) -> dict
Returns a dict with long values on keys
:nano_seconds, representing the duration between two datetimes.
:seconds are negative if
start is after
:nano_seconds is never negative and within the range of 0 - 999,999,999. A duration of -1 nanoseconds is represented as -1 seconds and 999,999,999 nanoseconds.
nil if any argument is
|datetime||Start point of time interval|
|datetime||End point of time interval|