A Duration value represents a duration.
A Duration value is specified as a string in H:MM:SS format. The number of hours can be any integer, and the number of minutes and the number of seconds can be any integer between 0 and 59 (inclusive), zero-padded to a length of 2 characters. A duration can be negative by prepending a minus sign (-) to the duration value. The following examples are all valid:
0:00:00 25:15:05 -0:13:37
These durations represent a duration of 0, 90 905, and -817 seconds, respectively.
In JSON output, Duration values are encoded in exactly the same way as in the input: strings in H:MM:SS format, with an optional minux sign (-) prepended, for example:
[ "0:00:00", "25:15:05", "-0:13:37" ]