To write the exact date, spell out the month, and write the day and the year in numerals. The American format is month-day-year, with a comma between day and year. In British style, which is day-month-year, no comma is needed between month and year.

How do you write two dates together?

I would write it as “August 4–5,” because the presentation is taking place on two consecutive days. (Nobody assumes it's a 48-hour presentation.) I would use “and” if the dates are not contiguous: “The concerts will be held on August 4 and 6.”

How do you write dates in formal writing?

In formal writing, always write the date in full when it is part of a sentence. This usually involves giving the day of the month, the month, and the year: The meeting will take place on April 21, 2019. Note that the year follows after a comma.