bug(date) incorrectly converts `%Y` to the Thai Buddhist calendar when `LC_TIME=th_TH.UTF-8` is set.

Reproducer

$ locale -k LC_TIME
abday="Sun;Mon;Tue;Wed;Thu;Fri;Sat"
day="Sunday;Monday;Tuesday;Wednesday;Thursday;Friday;Saturday"
abmon="Jan;Feb;Mar;Apr;May;Jun;Jul;Aug;Sep;Oct;Nov;Dec"
mon="January;February;March;April;May;June;July;August;September;October;November;December"
era=
alt_digits=

env -u LC_ALL LC_TIME=th_TH.UTF-8 \
./target/release/date -d "2026-06-14" "+%Y %B %A"

Actual output

2569 มิถุนายน วันอาทิตย์

Expected output

2026 June Sunday

GNU comparison

env -u LC_ALL LC_TIME=th_TH.UTF-8 \
date -d "2026-06-14" "+%Y %B %A"

GNU date prints:

2026 June Sunday

Notes

The active LC_TIME data contains:

mon="January;February;March;April;May;June;July;August;September;October;November;December"
day="Sunday;Monday;Tuesday;Wednesday;Thursday;Friday;Saturday"
era=
alt_digits=

However, uutils prints a Buddhist Era year (2569) and Thai month/weekday names.

This suggests that the formatter is not honoring the active locale data and is instead deriving formatting behavior directly from the locale identifier (th_TH.UTF-8).

Expected behavior is to match GNU date and use the values provided by the active LC_TIME definition.

Run the provided ./target/release/date reproducer with LC_TIME=th_TH.UTF-8, then compare its output with GNU date and the active LC_TIME values from locale -k LC_TIME. Done means %Y %B %A produces 2026 June Sunday instead of the Buddhist year and Thai names while preserving the locale behavior described by the issue.