Handling of day period format "b" seems incorrect

[dairiki]

Overview Description

The "b" format symbol to format_time and format_datetime (with locale="en") currently produces one of morning, noon, evening, or midnight.

The CLDR docs say the result should be one of am, noon, pm, or midnight.

(The latter behavior seems more useful.)

Steps to Reproduce

import datetime
from babel.dates import format_time

print(format_time(datetime.time(6), "h:mm b", locale="en"))

Actual Results

6:00 morning

Expected Results

6:00 am

Reproducibility

Babel versions 2.10.2 through 2.12.1 all behave consistently.
Versions prior to 2.10.2 do not support the "b" field at all (#869).

Additional Information

Comments:

• "6:00 am", "12:00 noon", "6:00 pm", "12:00 midnight" seems more usable than "6:00 morning", "6:00 evening".
• There is the "B" format field if one wants "in the evening".

[caitlinlilley]

Hi, if this issue is still available I would like to be assigned to it.

[jun66j5]

That is not a defect. In CLDR 42, morning is declared for period 6:00 <= time < 12:00 of "en" locale.

• https://github.com/unicode-org/cldr/blob/release-42/common/supplemental/dayPeriods.xml#L18
• https://github.com/unicode-org/cldr/blob/release-42/common/main/en.xml#L2350

>>> import babel
>>> babel.__version__
'2.12.1'
>>> import datetime
>>> from babel import dates
>>> dates.format_time(datetime.time(5, 59, 59), 'h:mm b', locale='en')
'5:59 night'
>>> dates.format_time(datetime.time(6, 0, 0), 'h:mm b', locale='en')
'6:00 morning'
>>> dates.format_time(datetime.time(11, 59, 59), 'h:mm b', locale='en')
'11:59 morning'
>>> dates.format_time(datetime.time(12, 0, 0), 'h:mm b', locale='en')
'12:00 noon'
>>> dates.format_time(datetime.time(12, 0, 1), 'h:mm b', locale='en')
'12:00 afternoon'
>>> dates.format_time(datetime.time(17, 59, 59), 'h:mm b', locale='en')
'5:59 afternoon'
>>> dates.format_time(datetime.time(18, 0, 0), 'h:mm b', locale='en')
'6:00 evening'
>>> dates.format_time(datetime.time(20, 59, 59), 'h:mm b', locale='en')
'8:59 evening'
>>> dates.format_time(datetime.time(21, 0, 0), 'h:mm b', locale='en')
'9:00 night'