Re: [ocpp] Re: Old OCPP 2.0 RC2 Time Zones description

[Anders Darander <anders@chargestorm.se>]

* Robert de Leeuw <robert.de.leeuw@ihomer.nl> [161107 17:23]:
> I have not received any remarks on this.
> Does that mean you all agree and this can be put into the specification?

I completely missed this one..

> 2016-10-21 6:59 GMT+02:00 Robert de Leeuw <robert.de.leeuw@ihomer.nl>:

> > Hi Bill,

> > As promised, hereby the text for Time as defined in the old OCPP 2.0 RC2
> > document.

> > 1.1      Time Zones & Daylight Saving Time 1.1.1          Time Zones

> > To improve interoperability between Central Systems and Charge Points all
> > time values SHOULD be exchanged as UTC, with the time zone designator ‘Z’,
> > as specified by ISO 8601.

This is good, standardizing on UTC for all CP <-> Backend communication
is really good.

> > For the purpose of displaying local time on a charge point’s display, the
> > device model’s Clock component supports specifying a time offset between
> > Central System time (UTC or otherwise) and local time at the Charge Point.
> > 1.1.2          Daylight Saving Time

> > To support punctual automated bi-annual changeover between “standard time”
> > and “daylight saving time” periods, the device model supports configuration
> > values of the Clock component that allow transitions between “standard” and
> > “daylight saving” time periods to be automated by specifying a “next”
> > transition date-time and a corresponding “next” time offset.

Just a question regarding the points above, do we foresee a large number
of tiny MCU's with displays in the CP's?

If not, I'd be strongly in favour of just using a timezone to handle
both the local offset as well as the daylight savings time. We have the
tzdata that's widely used in both (larger) embedded systems and other
OSes, see eg https://www.iana.org/time-zones.

I think that using a standard timezone definition makes sense; it
reduces the complexity of the CPO, especially a CPO that works across
timezones.

Cheers,
Anders

-- 
Anders Darander		Senior System Architect
ChargeStorm AB		Tel: +46 702 44 84 36
Hospitalsgatan 3	E-mail: anders@chargestorm.se
602 27 Norrköping	Web: www.chargestorm.se