ISO 8601 specifies a format of YYYY-MM-DD. 2003-04-02 is clearer than 03/04/02. (Some prefer to modify ISO 8601 by using an abbreviation for the month to make it more clear, for example 2003-Apr-02, but then it is no longer locale neutral.).
"国际标准化组织(ISO)规定,国际日期通用格式使用这种方式表示: YYYY-MM-DD"
科普一下ISO 8601
ISO 8601. Its full reference number is ISO 8601 : 1988 (E), and its title is "Data elements and interchange formats
参考文献
https://www.w3.org/International/questions/qa-date-format
https://www.w3.org/TR/NOTE-datetime