Using "midnight" to mean the beginning of the day could be confusing

[Jon Skeet]

Just as one extra wrinkle, if we define "midnight" to be "the time that one
day becomes another", it doesn't always happen at 00:00. If we define it to
be 00:00, it doesn't always occur.
I'm basically thinking about time zones (e.g. Brazil) which "spring
forward" at what would have been midnight, e.g.

23:59:58
23:59:59
01:00:00
01:00:01

Depending on your definition of midnight, it either doesn't happen or it
happens at 01:00. (Fortunately I don't *think* there are any examples where
00:00 occurs twice due to fall-back rules, although I wouldn't be
surprised.)

I'm not saying this is something we should fall out specifically - but it's
something we should be aware of when considering using the term "midnight".

Jon


On 22 January 2016 at 07:57, Mark Davis ☕️ <mark at macchiato.com> wrote:

> I think it really depends on context. I think the following, for example,
> refer to the same time, the instant between Tuesday and Wednesday.
>
>    - Wednesday, I was wide awake from midnight to 5am.
>    - Tuesday, the party lasted from 7pm to midnight.
>
> The context of a range makes it clear what was meant.
>
> I'm ok with holding back on using midnight, except when
>
>    1. there is a word for midnight in the locale that (predominantly)
>    means the start of the day (00:00).
>    2. in time intervals (where the context is then clear enough).
>    However, see below.
>
> Normally, date-time software views time-periods as half-open intervals.
> For example, the first hour of a day is from 00:00 to 00:59:59.9..., a day
> is from 00:00 to 23:59:59.9999..., a year is until Dec 31,
> 23:59:59.9999..., and so on.
>
> #2 is connected with a separate ticket which is to allow for the
> time-of-day to be *formatted* as being 24:00 or after. The primary use
> case for that is to allow time intervals (eg for opening hours) to span
> midnight, which are used in some countries, such as:
>
> Wednesday 18:00 – 25:00
>
>
> However, it could also allow for the use of a term "midnight" for 24:00,
> where that is the most natural expression.
>
> Mark
>
> Mark
>
> On Fri, Jan 22, 2016 at 7:40 AM, Martin J. Dürst <duerst at it.aoyama.ac.jp>
> wrote:
>
>> In my opinion, "could be confusing" is a gross understatement :-(. I just
>> recently wanted to submit some abstracts to a conference where I spent
>> about 10 minutes to figure out which end of a day the actual deadline was.
>>
>> While there may be conventions for such things in some communities, and
>> CLDR has an ambition to follow them, it's highly confusing in the world
>> wide context of the web. The less such things are made defaults, and the
>> more exact terms are used (e.g. "midnight at the start of the day" or some
>> such), the better.
>>
>> Regards,    Martin.
>>
>> On 2016/01/22 10:30, kz wrote:
>>
>>> Dear CLDR users,
>>>
>>> I'm currently trying to implement in ICU the pattern characters b and B
>>> for
>>> datetime formatting, which involves the use of the word "midnight". See
>>> http://www.unicode.org/reports/tr35/tr35-dates.html#Day_Period_Rules .
>>>
>>> Currently, according to the CLDR spec, the word "midnight" refers to
>>> 0:00,
>>> i.e. the beginning of the day. However, after a conversation with my
>>> colleagues, we feel that it's more natural for "midnight" to mean, at
>>> least
>>> in English, the end of the day. For example, "Wednesday midnight" would
>>> refer to midnight of Wednesday-Thursday, not the midnight of
>>> Tuesday-Wednesday. This could cause confusion to users.
>>>
>>> In addition, other languages could have different problems with the use
>>> of
>>> "midnight". For example, Chinese has two different words for "midnight
>>> (beginning of day)" (*lingchen*) and "midnight (end of day)" (*wuye*).
>>>
>>> As such, it'd probably be worth discussing to either (1) remove
>>> "midnight"
>>> as a time period, (2) use a different word for "midnight", or (3) modify
>>> spec to have "midnight" refer to the end of the day.
>>>
>>> Any opinions?
>>>
>>>
>>> Thanks
>>> kz
>>>
>>>
>>>
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>>>
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>
>
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