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bashmacosiso8601

`date` command on OS X doesn't have ISO 8601 `-I` option?

In a Bash script, I want to print the current datetime in ISO 8601 format (preferably UTC), and it seems that this should be as simple as date -I:

http://ss64.com/bash/date.html

But this doesn't seem to work on my Mac:

$ date -I
date: illegal option -- I
usage: date [-jnu] [-d dst] [-r seconds] [-t west] [-v[+|-]val[ymwdHMS]] ... 
            [-f fmt date | [[[mm]dd]HH]MM[[cc]yy][.ss]] [+format]

And indeed, man date doesn't list this option.

Anyone know why this is, or any other (easy) way for me to print the date in ISO 8601 format? Thanks!

Solution

  • You could use 

    date "+%Y-%m-%d"

    Or for a fully ISO-8601 compliant date, use one of the following formats:

    date -u +"%Y-%m-%dT%H:%M:%SZ"

    Output:

    2011-08-27T23:22:37Z

    or

    date +%Y-%m-%dT%H:%M:%S%z

    Output:

    2011-08-27T15:22:37-0800