[Tagging] Opening hours + daylight saving time

[Warin]

On 15/11/2015 9:38 PM, Robin Schneider wrote:
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> On 15.11.2015 00:55, Warin wrote:
>> On 14/11/2015 9:03 PM, Robin Schneider wrote:
>>> On 14.11.2015 09:15, Warin wrote:
>>>> Hi,
>>>>
>>>> I need to combine daylight saving times with opening hours ... For
>>>> example open 8:300 to 17:00, except for daylight saving times where it
>>>> is open 8:30 to 18:00.
>>>>
>>>>
>>>> Possible ? opening_hours=ndst 8:30-17:00; dst 8:30-18:00
>>>>
>>>> where ndst = non daylight saving time dst = daylight saving time
>>>>
>>>> dst is suggested in
>>>> http://wiki.openstreetmap.org/wiki/Proposed_features/access_restrictions_1.5
> Hi
>>> This can already be expressed. Check
>>> https://wiki.openstreetmap.org/wiki/Talk:Key:opening_hours#Daylight_Savings
>> Err no. That is an energy savings measure that is effective all year.
>>
>> Daylight Savings Time (or Summer Time) is a periodic adjustment of the
>> local clocks to make more effective use of the increased daylight
>> available.
>>
>> Reference: https://en.wikipedia.org/wiki/Daylight_saving_time
>>
>> The effective Daylight Savings Time dates change with the whim of some
>> politicians/bureaucrats, so fixed dates cannot be used.
> All right. Luckily most regions in Australia seem to have agreed on common
> dates when the change to DST takes place [1]. But this is different for your
> region? So whoever makes up those dates when the change takes place needs to
> make a list … That makes things more difficult :( (like many other things when
> working opening hours).

http://www.australia.gov.au/about-australia/facts-and-figures/time-zones-and-daylight-saving

The decision is done by each State Government.

In the past  differing states had different dates to start and stop ..

and differing dates from one year to the next

  ..... made things complicated! Looks like 'they' have agreed to be sensible.
That may not continue as new people get elected and jobs change.

>
> Just to get this straight, what did you mean with the energy savings measure
> which is effective all year? Is that the reason for the individual dates made
> up by politicians/bureaucrats?

The 'effective all year' came from your reference to the OSM wiki on 'daylight saving' ... that is applied all year.
I will make an addition to that section of the OSMWiki when I decide what I'm going to do.

>
> Furthermore, since you now found a good reason to introduce timezone support
> to opening_hours, could you write an proposal for it?

I can simply use the present dates ... but these may change and need editing then.

It would be simplest to use the present dates for me and probably for all OSM.


>
> Things which would be nice to have in a proposal addressing your problem:
>
> * URL to the definition list when the changes take place and for which region
> * Those regions would need to be differentiable in OSM and preferable via
> Nomination.

Simplest would be

https://en.wikipedia.org/wiki/Daylight_saving_time_by_country

However I expect the individual countries will have a government URL with the legally correct and up to date official times.

>
> I see two different ways to tag this:
>
> 1. AEST 8:30-17:00; AEDT 8:30-18:00
>
> + Shorter
> - - Might not be easy to see that AEDT is a timezone
>
> 2. tz=AEST 8:30-17:00; tz=AEDT 8:30-18:00

tz? time zone?

I would 'see'  AEST, AEDT, etc  to be similar to June, July etc .. part of the 'year'. The 'zone' bit should not be relevant - already taken care of by the mapper.


>
> Just a thought but I expect that this is not really easier for the regular mapper?
>
> + key=value datatype in the opening_hours value
> + would allow more extentions to the syntax in the future which can follow
> this format
> + 3 characters more for each rule
>
> [1]:
> https://en.wikipedia.org/wiki/Time_in_Australia#Daylight_saving_time_.28DST.29
>
>>> When you really want to propose a better/shorter syntax for it I would
>>> recommend to use already defined timezone codes [1].
>>>
>>> [1]: https://en.wikipedia.org/wiki/List_of_time_zone_abbreviations
>> Humm yes. I think. It would make my example
>>
>> opening_hours=AEST 8:30-17:00; AEDT 8:30-18:00
>>
>> where AEST = non daylight saving time (Australian Eastern Standard Time)
>> AEDT = daylight saving time (Australian Eastern Daylight savings Time)
>>
>> Note the change in closing time! During Daylight Savings Time the closing
>> is one hour later.
>