The Weekend Event runs on Saturday and Sunday. You need to complete various game tasks. There can be a maximum of three tasks available at a time.
When a task is completed, you get the next one. A task can be replaced once per day for free, and for rubies or watching ads afterward.
There may be an occasional timeout for receiving tasks, which you can skip for rubies or watching ads.
You get a prize and reward tokens for each completed task.
In addition, there are rewards for completing weekend event stages. To receive such a prize, you need to accumulate a sufficient amount of reward tokens.
The event icon is located in the right menu of the Home Screen.