CDUB - CountDown-Up Big
This module displays a countdown to a specific date. Once the date is reached, a countup can be displayed. The countup shows the elapsed time after the event.
You can enter as many events as you need. Once one event is expired, the next event is loaded automatically. The module offers several settings, such as: link to further information of the event before and after the event date, own text (HTML-Tags) etc. The counter can be displayed statically or dynamically.
Joomla! 3.x - https://joomla-extensions.kubik-rubik.de/downloads/cdub-countdown-up-big/joomla-3
The extension is completely free, but you need a subscription for support: