Function prefers_12_hour_clock 

pub fn prefers_12_hour_clock(tag: &str) -> bool

Whether the given locale prefers a 12-hour clock (with AM/PM) for digital-UI time display. Returns false (24-hour) for any locale not explicitly listed — matching CLDR’s behaviour for the vast majority of locales worldwide. The few true cases are the English-speaking regions where digital-UI 12-hour display is the near-universal convention: US, Canada, Australia, New Zealand, Philippines, plus the en-IN/en-PK digital convention. Lookup is longest-prefix match, identical to format_pattern_for_locale and first_day_of_week_for_locale.