Show whose clock the appointment uses

A customer can reserve a Costa Rica appointment while using a device set to another time zone. A plain time such as 9:00 leaves room for misunderstanding. The interface should make the appointment's local context explicit.

Choose the reference time

Decide whether the service is scheduled by its Costa Rican location or by the customer's location. An in-person pickup generally needs a clear service-location time. A remote consultation may need both parties' local views. The business should choose the rule before the developer formats the clock.

Keep the confirmation consistent

The booking screen, email and staff calendar should describe the same appointment. Avoid converting the time in one place and leaving an unlabeled number elsewhere. A customer changing a device setting should not accidentally change the stored commitment.

Test a different device zone

Use fictional appointments and a browser configured for another region. Check the selected date, confirmation and calendar export. Include an appointment near midnight so a date change becomes visible.

MDN's date-formatting documentation describes explicit locale and time-zone options. Correct formatting is only part of the workflow; the stored appointment and provider integration must follow the same rule. Bring the scheduling context to a reservation-system discussion.