Last updated at 6:27 pm UTC on 3 April 2018
I represent a point in UTC time as defined by ISO 8601. I have zero duration.
My implementation uses three SmallIntegers and a Duration:
1. jdn - julian day number.
2. seconds - number of seconds since midnight.
3. nanos - the number of nanoseconds since the second.
offset - duration from UTC (possibly nil if no timezone information)
The nanosecond attribute is almost always zero but it defined for full ISO compliance and is suitable for timestamping.