Dev req to Complete Dynamic Calendar Feature with vis.js

I am seeking an experienced developer to finalize the integration of a dynamic calendar feature into an existing web-based employee training management application. This feature should provide a monthly view, displaying completed events such as trainings, meetings, and feedback for each employee. It should also indicate the week number for each week, allow filtering by time period and event type, and dynamically reflect any changes in employee status, updating to show past events accurately.

The application is developed using procedural PHP, MySQL, jQuery, and Bootstrap, and this new feature needs to be implemented following the MVC architecture utilizing OOP in PHP.

Current Progress:

MVC structure is already implemented in the project.
Database connections are established, and PHP classes have been set up.
vis.js has been integrated with an initial example configured.
Initial attempts have been made to display a list of employees from the database on the page, but this is not completed.

Requirements:

Complete Employee List Display:

Fetch and display the list of employees on the calendar from the database.

Events Display and vis.js Customization:

Fetch and display past trainings, team meetings, and feedback events on the timeline, corresponding to each listed employee.

Customize event display in vis.js with distinct colors for each type of event:

Blue background with a centered 'M' for Meetings.

Green background with a centered 'S' for Schulungen (Trainings).

Orange background with a centered 'B' for Bewertung (Feedback).

Event Filters and Date Picker Implementation:

Implement checkboxes to filter the timeline display by event type.

Integrate a "Month and Year only" date picker to allow users to select which month and year to view.

Real-Time Updates:

Ensure the calendar updates dynamically when new employees are added or existing employees leave the company.

Automatic Event Update Logic for Calendar Feature:

Implement an automatic update mechanism that ensures past events are dynamically displayed in the timeline.

Deadline:
I need this completed within a maximum of 4 days.

Tools and Technologies:
MVC, OOP PHP, MySQL, PDO, vis.js, JavaScript, fetch API, HTML, CSS, Bootstrap.