plain/locale
getLocaleEraNames: Return a locale’s Gregorian era names as [BCE-label, CE-label].getLocaleMeridiems: Return a locale’s AM/PM (day-period) labels as[AM-label, PM-label].getLocaleMonthNames: Return the 12 Gregorian calendar-month names for a locale, in calendar order (January first, December last — not alphabetical).getLocaleWeekdayNames: Return the 7 weekday names for a locale, ordered starting from the locale’s first day of the week.