Is it possible for the time slots to be reset every hour?

Nos gustaría poner límites por cada horario en la agenda, que las personas puedan escoger ese horario,hasta que se complete el aforo disponible: 20

Hi Esteban,

Thanks for reaching out to Jotform Support. Unfortunately, our Spanish Support agents are busy helping other Jotform users at the moment. I'll try to help you in English using Google Translate, but you can reply in whichever language you feel comfortable using. Or, if you'd rather have support in Spanish, let us know and we can have them do that. But, keep in mind that you'd have to wait until they're available again.

Now, coming back to your question, unfortunately, it is not possible to set limits for each time slot and have it automatically reset every hour. However, you can change the appointment type to Group and specify a maximum number of attendees and when the time is over, you can delete the submissions to make them available again. Let me show you how:

1. In Form Builder, select the Appointment's Gear icon to open properties.
2. Go to Advanced tab.
3. Under Appointment Type, choose Group and set the Maximum Attendees Per Time Slot to 20. 

This will limit all of your time slots to 20 and when one of your time slots or time slots has hit the 20 limit. They will be greyed out, but you can remove the entries that choose the time slots to make them available again in the following hour. This will need you to do everything manually, but it is the closest to what you need.

Let us know if you have any other questions.