---
title: "bash built-in date"
url: https://perrotta.dev/2024/10/bash-built-in-date/
last_updated: 2025-09-05
---


To format dates [GNU
date](https://www.gnu.org/software/coreutils/manual/html_node/Examples-of-date.html)
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/