get_period_id() incorrectly handles day period rule crossing 0:00 since Babel 2.4.0

[jun66j5]

Overview Description

According to https://github.com/unicode-org/cldr/blob/release-41/common/supplemental/dayPeriods.xml#L15-L22, there is dayPeriodRule crossing 0:00 for en locale.

<dayPeriodRules locales="en">
        ...
        <dayPeriodRule type="night1" from="21:00" before="06:00"/>      <!-- night -->
</dayPeriodRules>

I noticed get_period_id() incorrectly handles this day period rule.

>>> dates.get_period_id(time(23), locale=en_US)
'pm'  # => should be 'night1'
>>> dates.get_period_id(time(1), locale=en_US)
'am'  # => should be 'night1'

Steps to Reproduce

>>> from datetime import time
>>> from babel import Locale, dates
>>> en_US = Locale.parse('en_US')
>>> dates.get_period_id(time(23), locale=en_US)
'pm'  # => should be 'night1'
>>> dates.get_period_id(time(1), locale=en_US)
'am'  # => should be 'night1'
>>> en_US = Locale.parse('en_US')
>>> for h in range(24):
...   t = time(h)
...   print(t, dates.get_period_id(t, locale=en_US))
...
00:00:00 midnight
01:00:00 am
02:00:00 am
03:00:00 am
04:00:00 am
05:00:00 am
06:00:00 morning1
07:00:00 morning1
08:00:00 morning1
09:00:00 morning1
10:00:00 morning1
11:00:00 morning1
12:00:00 noon
13:00:00 afternoon1
14:00:00 afternoon1
15:00:00 afternoon1
16:00:00 afternoon1
17:00:00 afternoon1
18:00:00 evening1
19:00:00 evening1
20:00:00 evening1
21:00:00 pm
22:00:00 pm
23:00:00 pm

Actual Results

>>> dates.get_period_id(time(23), locale=en_US)
'pm'
>>> dates.get_period_id(time(1), locale=en_US)
'am''

Expected Results

dates.get_period_id(time(23), locale=en_US) and dates.get_period_id(time(1), locale=en_US) should return 'night1'.

Also, we should add unit tests for get_period_id().

Reproducibility

The issue occurs with Babel 2.4.0 and later, however doesn't with 2.3.0 - 2.3.4.

Additional Information

It seems to be caused by changes of day period rule between Babel 2.3.4 (CLDR 28) and 2.4.0 (CLDR 29).

See also 8th list in https://unicode.org/reports/tr35/tr35-dates.html#4512-variable-periods

>>> import babel
>>> babel.__version__
'2.3.4'
>>> en_US = babel.Locale.parse('en_US')
>>> for _ in en_US.day_period_rules.get(None, {}).items(): _
...
('noon', [{'at': 43200}])
('morning1', [{'from': 21600, 'before': 43200}])
('afternoon1', [{'after': 43200, 'before': 64800}])
('night1', [{'after': 0, 'before': 21600}, {'from': 75600, 'before': 86400}])
('evening1', [{'from': 64800, 'before': 75600}])
('midnight', [{'at': 0}])

>>> import babel
>>> babel.__version__
'2.4.0'
>>> en_US = babel.Locale.parse('en_US')
>>> for _ in en_US.day_period_rules.get(None, {}).items(): _
...
('midnight', [{'at': 0}])
('noon', [{'at': 43200}])
('morning1', [{'before': 43200, 'from': 21600}])
('afternoon1', [{'before': 64800, 'from': 43200}])
('evening1', [{'before': 75600, 'from': 64800}])
('night1', [{'before': 21600, 'from': 75600}])

[akx]

Great catch!

I suspect the breaking commit was 34c92cb.

[akx]

Fixed by #871.