bash built-in date

07 Oct, 2024 • 48 words • 1 min • updated 05 Sep, 2025

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To format dates GNU date is often used:

     shell
     
   
$ date '+%Y-%m-%d'
2024-10-07

It turns out bash (>=4.2) has this feature built-in as part of printf:

     shell
     
   
$ printf '%(%Y-%m-%d)T\n'
2024-10-07

It does not work on zsh though:

     shell
     
% printf '%(%Y-%m-%d)T\n'

printf: %(: invalid directive

Source: https://blog.marco.ninja/notes/technology/linux/working-with-dates-in-bash-and-other-shells/