As with many things in Chinese, dates are arranged from largest unit to smallest: year, month, day.

Dates in Chinese follow the order "year, month, day."

Structure

So April 1st, 2013 is 2013年4月1日.

Note that 号 is commonly used in spoken Mandarin instead of 日: 2013年4月1号. In written Chinese, however, you will see 日 rather than 号.

Examples
1940年11月27日
November 27th,1940