I wanted to-rebuild / re-deploy my Vercel site every hour, to pull in fresh content.
To do this, go to your Vercel dashboard and open the site that you want to re-deploy on a schedule. Then click on the Settings tab, Git on the sidebar, and scroll down to Deploy Hooks. Create a new hook and copy the URL.
Any time a request is made to this URL, your site will be re-built and deployed.
Next, make an account at cron-job.org, which allows you to have free scheduled jobs.
There, create a new cron job to execute every hour (or more/less often, if you want) and have it make a request to the Vercel hook URL that you created earlier.
Now, cron-job.org will make a request to the Vercel deploy hook every hour, triggering a new deploy for your site.