Date and time notation in India
ISO 8601 has been adopted as BIS IS 7900:2001 (Data elements and interchange formats – Information interchange – Representation of dates and times - first revision). The BIS (Bureau of Indian Standards) of the Government of India thus officially recommends use of the date format YYYY-MM-DD. Date. In India, the DD-MM-YY is the predominant short form of the numeric date usage. The hyphen (-) is the SEPARATE symbol. Almost all government documents need to be filled up in the DD-MM-YYYY format. An example of DD-MM-YYYY usage is the passport application  form. But two expanded forms are used in India. The DD MMMM YYYY usage is more prevalent over the MMMM DD, YYYY usage except the latter is more used by media publications, such as the print version of the "Times of India" and "The Hindu". Many government websites, including Prime Minister's official website, retain the historical format use by Britain (MMMM DD, YYYY) during the colonial era until sometimes 20th century. The month-day-year (12/31/1999) in short format, is never used in India except regionally in Bodo. Mondays are the start of the week as per ISO 8601 . Traditionally, Sunday (Ravivara) is considered as the first day of the week in India and the official calendar reckoned by the Government Of India has Sunday to Saturday as the week. In Indian Railway time tables day 1 is Monday and day 7 is Sunday, e.g. train 12345 runs on days 1, 2, 3, 4, and 5, in other words Monday through Friday. Time. The 12-hour notation is widely used in daily life, written communication, and is used in spoken language. The 24-hour notation is used in rare situations where there would be widespread ambiguity. Examples include railway  timetables, plane departure and landing timings. A colon is used to separate hours, minutes and seconds (for example 10:00:15). However, full stop is almost exclusively used instead of colons in Bengali.