USA date format best practise

1. How is date format written in USA?
2. What is the best practice for date format?

How is date format written in USA?

In America, the date is formally written in month/day/year form. Thus, “January 1, 2011” is widely considered to be correct. In formal usage, it is not appropriate to omit the year, or to use a purely numerical form of the date.

What is the best practice for date format?

For date, always include four digit year and use numbers for months. For example, the date format yyyy-mm-dd would appear as 2011-03-15 (March 15, 2011). If Julian day is used, make sure the year field is also supplied. For example, mmm.