How can I automatically insert the current date into the YAML footer in Quarto Reveal.js?

I am using Quarto to create a Reveal.js presentation. My YAML looks like this:

---
format:
  revealjs:
    footer: "Footer text"
---

I would like the footer to always show the current date (i.e., the date the presentation is rendered), like this:

Footer text | Last updated: 2025-06-17

Is there a way to automatically insert the current date into the footer via a variable, shortcode, or Quarto/YAML syntax?

I tried using {date}, {{< date >}}, and {{< last-modified >}}, but these are either not rendered or cause errors in the YAML footer.

Hardcoding the date works, but I want it to update automatically on each render.

Is there a built-in way to do this, or do I need a workaround (such as a script to edit the YAML before rendering)?

You can use date: today (or try last-modified):

---
format:
  revealjs:
    footer: "Footer text | Last updated: {{< meta date >}}"
date: today
---