In Italy, the all-numeric form for dates is in the order "day month year", using a stroke as the separator. Example: 31/12/1992 or 31/12/92. Sometimes a dot or a hyphen is used instead of the stroke. Years can be written with two or four digits, and day and month may be written with or without a leading zero. Months and week days are generally written with a lowercase letter, since they are not considered proper nouns. A very common spelling mistake is to drop the final accent in week days names from lunedì to venerdì : thus lunedi, martedi, mercoledi, giovedi, venerdi are all wrong. The other format is "year month day", also used when specifically in computing texts to avoid ambiguity from DMY format. Example is 1992-12-31. The expanded form is "22 dicembre 2010", optionally with the day of the week: "mercoledì 22 dicembre 2010". The first day of the month is usually written 1º dicembre or 1° dicembre; 1 dicembre is also considered correct. This can either be pronounced il primo dicembre or l'uno dicembre. The other days of the month always follow the cardinal form. Two-digit years may be used in the expanded form, but in this case they are prefixed by an apostrophe: " 22 dicembre '10". This notation is considered informal. Sometimes it can be found also " 22 dicembre '010". The first day of the week in Italy is Monday, but for the Church the first day is Sunday.
Time
The 24-hour notation is used in writing with a dot or a colon as a separator. Example: 14.05 or 14:05. It is also common to use the comma as a separator. The minutes are written with two digits; the hour numbers can be written with or without leading zero. In oral communication 12-hours are prominently used since 24-hours are considered very formal. In 12-hours, hour figures are always preceded by the definitive article and a.m. or p.m. are never used. L'una di pomeriggio is 1 p.m., le due is 2 p.m., le tre is 3 p.m. etc. Hours after sunset or dusk are given as le sette di sera, le otto di sera and so on until 11 p.m. which is le undici di sera. Midnight is simply mezzanotte. Following hours are l'una , le due or sometimes l'una del mattino, le due del mattino. After dawn, hours are le otto , le nove until 11 a.m. Midday is mezzogiorno. 12-hours may be used with approximate time, such as le tre e un quarto or with precise time. Whether one is referring to a.m or p.m. is generally implicit in the context of the conversation; otherwise, more information must be provided in order to avoid confusion: le tre e diciotto del pomeriggio. In some parts of the country only mattina e sera are used in everyday speech: thus le due di sera is 2 p.m. or 14:00 and le due di mattina is 2 a.m. or 02:00. Furthermore, in Tuscany, until recent times, l'una was virtually unknown: Tuscans used to say il tocco instead for both 1 p.m. or 13:00 and 1 a.m. or 01:00.