How do I trigger a job scheduled for later by setting #runAt?

Hi!

I have a habit tracker on my app, and every time I mark that I have for example exercised today, I want to schedule an action to be performed just after midnight (at the users LocalTime), meaning at the very start of the following day.

As far as I understand, I can create a job and set a #runAt date timestamp so the job will run later, but it is a bit unclear to me how it would work.

Will that job trigger by itself at the given time, or would I need to run some command from a script triggered by a cron job?

Will be using IHP Cloud in production.