Latepoint Timezone Locker (LTL)

Latepoint Timezone Locker (LTL) is an add-on for the Latepoint appointment booking plugin in WordPress.

IMPORTANT:

At this moment, LTL is not an official Latepoint© Add-on. It is not built or endorsed by Latepoint©. Hopefully it will be.

LTL was created by me to solve my problem.

!!! Knowing this use it at your own risk !!!

Latepoint Timezone Locker ensures that all displayed appointment times strictly follow the timezone set in the WordPress settings, preventing adjustments based on the user’s local timezone.

LTL is designed for a very specific use case: when all appointments take place at a fixed physical location. For example, a surgery clinic in one country that schedules appointments with patients from different time zones. Since patients are expected to travel to the clinic, maintaining a consistent local time for bookings is essential.

By locking appointment times to the site’s configured timezone, LTL provides a unified and reliable scheduling experience for both administrators and clients.

Version: LTL 1.2.2 Date: 31-03-2025

Key aspects of Latepoint and strategy

Looked into start.php and feature_timezone_helper.php.

get_wp_timezone() / get_wp_timezone_name(): These methods retrieve the timezone set in WordPress settings.

get_timezone_name_from_session(): This method is key!

It attempts to get a timezone name, likely from a user's previous selection or detection.

It uses a cookie: $_COOKIE[Latepoint_SELECTED_TIMEZONE_COOKIE]. This suggests the user's browser timezone might be detected client-side (JavaScript) and stored in this cookie. [Latepoint_selected_timezone_70e10ec56ce92acf0cfbc7d18546983e]

Crucially, it includes a filter: apply_filters('Latepoint_timezone_name_from_session', $timezone_name);. This is the perfect place for LTL to intervene! Hook into this filter and force it to always return the WordPress timezone name.

set_timezone_name_in_cookie(): Confirms that Latepoint can set this cookie. Our filter should override the reading of this cookie for timezone calculations.

Debug

Define LTL_DEBUG as true in wp-config.php to enable PHP error logging

define('LTL_DEBUG', true);