Nanosecond resolution for Time and Date, TimeZones
Author JeffreySarnoff
31 Stars
Updated Last
1 Year Ago
Started In
December 2017


Nanosecond Resolvable Dates, Times, DateTimes, TimeZones

Copyright © 2018..2022 by Jeffrey Sarnoff.    The MIT License applies.

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This package expects Julia v1.6.3 or higher

pkg> up
pkg> add TimeZones
pkg> add CompoundPeriods TimesDates


using TimesDates, CompoundPeriods, TimeZones, Dates

The Design

This package provides TimeDate to hold the date and time of day given in nanoseconds (or more coarsely). And providesTimeDateZone to holds the the date and time of day in nanoseconds with a timezone. This work relies heavily on Dates and TimeZones; most of the attention to detail plays through.

Dates has a Time type that has nanosecond resolution; it is not well supported, even within Dates. This Time type recognizes strings only if they are limited to millisecond resolution. Only millisecond resolved times are relevant to DateTimes. While at present limited by this millisecond barrier, TimeZones is a laudable package with active support. I expect an eventual melding of what's best.

Here, the inner dynamics rely upon the Period types (Year .. Day, Hour, .., Nanosecond) and CompoundPeriod all provided by Dates. We distinguish slowtime, which is millisecond resolved, from a nanosecond resolved fasttime.

The general approach is separate the date, slowtime, fasttime, and timezone (if appropriate), then use the date, slowtime and timezone (if appropriate) to obtain a coarse result using the facilities provided by the Date and TimeZones packages. We refine the coarse result by adding or subtracting the fasttime, as appropriate.


This work is built atop Dates and TimeZones.

While both are collaborative works, a few people deserve mention:

  • Dates: Jacob Quinn and Stefan Karpinski
  • TimeZones: Curtis Vogt
  • early work on timezones: Avik Sengupta

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