Skip to main content

[JSR-354] CanadianMinds on Timestamp and Currency

  • From: Werner Keil <werner.keil@...>
  • To: jcurrency_mail@...
  • Subject: [JSR-354] CanadianMinds on Timestamp and Currency
  • Date: Thu, 4 Apr 2013 13:39:19 +0200

I don't know, if some of his work in this area may have been in the references and Wiki before, but in any case, the work of Java early day pioneer and Software Design mastermind Roedy Green looks very helpful.

First of all, he not only created Date/Time APIs and solutions combining e.g. java.util.concurrent with existing Date/Calendar and a bit of his own code (something like BigDate, not sure if it's like BigDecimal or Joda BigMoney, but the idea must have come from one of those) plus great stuff like a HolidayCalculator API on top of these as early as  1996 (the Concurrency Utilities came out later, so he added those to his solution) all in all adding some superior value over any of the 4(!) Date/Time APIs, that Java 8 now comes with (TimeUnit and related classes in Concurrency Utilities, Date/Calendar, JavaFX Duration and the package formerly known as JSR 310

Related to that he also explains, why a UTC Timestamp using ANY of these Java Date/Time APIs and the local system time is unreliable and can't be trusted for some sensitive use cases like Real Time Trading, etc.
So even if these users and traders may be just a small fraction of the JSR 354 user base, using a UTC timestamp instead of baking in either java.util.Date or some "Temporal" implementation from 310 allows to store a timestamp derived from a trusted and reliable source where needed

Maybe the banking customers of some members here do not have such high standards and requirements, but be sure, there are some who do, and this way we're not restricted to some API that only relies on internal clock

Roedy also provides phantastic background material and sample code for Currency
and Conversion

The first link and various "toMinor" rates for a long-based currency implementation look extremely useful.
Unless he's already there, let's make sure, his site is also mentioned in the EDR external links.

As I may have mentioned, at least to Anatole, important personal matters in Vienna kept me there a bit longer. Thus Anatole is going to present JSR 354 alone in Berlin tomorrow. Lucky me, the Bitcoin Austria User Group Meeting was this Tuesday and I was honored to represent the JCP and JSR 354 in an exclusive Feature length documentary abou Bitcoin. If some of you have something to say especially about Bitcoin, they are touring other countries, e.g. Scandinavia and Silicon Valley later this year. See

Kind Regards,


Werner Keil | JCP Executive Committee Member | Eclipse UOMo Lead, Babel Language Champion | Java Godfather

Twitter @wernerkeil | @JSR354 | #Java_Social | #EclipseUOMo | #OpenDDR

Skype werner.keil | Google+

* JavaOne Russia: April 23-24 2013, Moscow, Russia. Werner Keil, JCP Executive Committee Member, JSR 354/360 EG Member will present "JSR 321, JSR 354, Standards for the Future of Java Embedded"

* GeeCON: May 16-17 2013, Krakow, Poland. Werner Keil, JCP Executive Committee Member, JSR 360 EG Member will present "Standards for the Future of Java Embedded"

[JSR-354] CanadianMinds on Timestamp and Currency

Werner Keil 04/04/2013
Please Confirm