The little-endian format is the most popular format worldwide, followed by the big-endian format. Dates may be written partly in Roman numerals or written out partly or completely in words in the local language.
Time
The 24-hour clock enjoys broad everyday usage in most non-English speaking countries, at least when time is written or displayed. In some regions, for example where German, French, and Romanian are spoken, the 24-hour clock can be used even when speaking casually, while in other countries the 12-hour clock is used more often in spoken form. In most English-speaking regions, particularly the United States and the Commonwealth, the 12-hour clock is the predominant form of stating the time, with the 24-hour clock used in contexts where unambiguity and accurate timekeeping are important, such as for public transport schedules. Nonetheless, usage is inconsistent: in the UK, train timetables will typically use 24-hour time, but road signs indicating time restrictions typically use 12-hour time, e.g. "Monday–Friday 6.30–8.30pm". The BBC website uses the 24-hour clock for its TV and radio programme listings, while BBC promotions for upcoming programmes give their times according to the 12-hour clock. Punctuation and spacing styles differ, even within English-speaking countries. Most people in "24-hour countries" are so used to both systems being alternately used in spoken language that they have no problem switching between the two, perceiving the statements "three o'clock" and "15:00" simply as synonyms. When speaking, a person may often pronounce time in 12-hour notation, even when reading a 24-hour display. It is also common that a person uses the 24-hour clock in spoken language when referring to an exact point in time, while using some variant of the 12-hour notation to refer vaguely to a time. However, encountering a p.m. time written in the 12-hour notation is likely to cause confusion with people used to the 24-hour written notation. In certain languages such as Spanish, Portuguese, Dutch, and English the hour is divided into quarters and halves, spoken of relative to the closest hour. In Arabic, thirds of an hour are also used. In Czech language quarters and halves always refer to the following hour, e.g. čtvrt na osm meaning 7:15, půl osmé meaning 7:30 and tři čtvrtě na osm meaning 7:45. Russian language uses the same convention: четверть восьмого, полвосьмого, без четверти восемь meaning 7:15, 7:30, 7:45 respectively. In many Germanic languages except English, the half-hour refers to the next hour. In colloquial language, this can cause confusion between English and German. In conversational English as spoken in the UK, half past eight is often reduced to half eight. But in German halb acht, Dutch half acht, and Swedish halv åtta, all invariably mean 7:30. For the quarters, in German different dialects use Viertel nach sieben or viertel acht, and Viertel vor acht or dreiviertel acht. In the French language, the quarters are expressed as additions or subtractions of the full hour: sept heures et quart, sept heures et demie, huit heures moins le quart. It's also common to use this format in Portuguese, specifically in the northern part of Portugal. In France and Vietnam, the common separator between hours and minutes is the letter "h".
