Create a countdown Add-on for a CMS

Familiarity with Concrete5 CMS is a plus. Need to create a countdown add-on. The adding will allow a user to add multiple weekly events. And the countdown should countdown to the next event. And while the event is going on, a link to watch it live should appear. So let's say I add a reoccuring event that happens every sunday, and wednesday at 7pm-9pm. On friday, it should say how many days, hours, and minutes until the sunday event. At 7pm on sunday, it should remove the countdown and provide a link to the live video feed. After 9pm on sunday (after the event), it should start the countdown to the next event (wednesday 7pm). Please the attached screen shot mockup, and the desired markup.