There are various ways of writing calendar dates in English. We can talk about writing formally or informally, and using the British or American style. British and American styles are quite unique in their different ways. Basically, British English format is day—month—year, while American English uses month—day—year.
British English Dates Writing (day—month—year)
13 October 2016
13th October 2016
13th of October 2016
the 13th of October 2016
Wednesday, 13th October 2016
Any of the above are used in British English and formal writings use the complicated ones. Note that the use of a comma before the year and of before the month are optional, and not common in British English. However, a comma is usually used when the date is within a sentence (…October, 2016).
Numerically, dates in British English are shown in the following examples:
American English Dates Writing (month—day—year)
October 13, 2016
Thursday, October 13, 2016
Note that you might use March the 9th or March 9th in American English, but it is less common because Americans rarely use ordinal numbers (1st, 3rd, 2nd, 5th).
Numerically, American English uses the following:
Generally, we use abbreviated months’ names, with the exception of May and June(though Americans use ‘Jun.’): Jan, Feb, Mar, Apr, Jul, Aug, Sep, Oct, Nov, Dec.
When asked ‘What day is it?’, ‘What’s today’s date?’ or ‘What’s the date today?’, we could reply ‘It’s the thirteenth of October’, ‘It’s thirteen of October’ or ‘It’s October the thirteen’.
When talking about years, we can say two thousand and sixteen or twenty sixteen (2016); two thousand and two or twenty oh two (2002); the nineteen twenties (1920s), etc.