Twenty-four hour clock object with nanosecond precision.
A the Time::Clock manpage object is a twenty-four hour clock with
nanosecond precision and wrap-around. It is a clock only; it has absolutely
no concept of dates. Vagaries of date/time such as leap seconds and
daylight savings time are unsupported.
When a the Time::Clock manpage object hits 23:59:59.999999999 and at least
one more nanosecond is added, it will wrap around to 00:00:00.000000000.
This works in reverse when time is subtracted.
the Time::Clock manpage objects automatically stringify to a user-definable