The event is available to all players level 7+, who spent more than 7 days in the game after installing The Tribez for the first time.
If your game account complies with the basic terms of the event, you just need to interact with any worker in the game and make him do something, e.g. cut down a tree or clear the area of weeds. After that, the event will begin.

The event itself is time-limited and lasts for 3 days. Respectively, if it begins on Friday noon in accordance with the schedule, it will end on Monday noon. Note that if you join the event on Saturday it will still end on Monday.