# Date format: YYYY-MM-DD

Currently I put the date in my document using: \date{\today}

How do I display the date in the YYYY-MM-DD format?

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See here ctan.org/pkg/datetime From the documentation (pg 10) we have The option yyyymmdd makes \today produce YYYY/MM/DD date –  Sigur Jan 4 at 13:30

Using the package datetime with the option yyyymmdd as

\usepackage[yyyymmdd]{datetime}


you just change the value of \dateseparator to replace the default / by - (or -- if you want).

\renewcommand{\dateseparator}{--}


Also as noted by @Vincent, you can define your own date format.

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Somebody should check whether ISO 8601 says that the separator has to be - or --. (iso.org/iso/home/standards/iso8601.htm). Definitely YYYY/MM/DD should not be used - that would violate the standard. Keith –  KeithB Jan 8 at 9:53
@KeithB, Wikipedia claims, “The separator used between date values (year, month, week, and day) is the hyphen”. Also, it’s unlikely the standard mandates characters encoded neither in EBCDIC nor ASCII. –  J. C. Salomon Jan 13 at 19:20

According to the link of Sigur:

\usepackage{datetime}
\newdateformat{specialdate}{\THEYEAR-\twodigit{\THEMONTH}-\twodigit{\THEDAY}}
\date{\specialdate\today}

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Use the package isodate
\usepackage[iso,german]{isodate}