As it has done in 2017 and 2018, Apple will once again challenge all Apple Watch wearers around the world to go out on April 22 and complete any workout for at least 30 minutes.

Completing the challenge will net you a virtual medal under the Achievements tab in your iPhone’s Activity app along with a special sticker that can be used in Messages and FaceTime.

Any workout will do, including a workout started in your favorite third-party app as long as it writes data to the Activity app. This challenge will launch for all Watch wearers globally.

Here’s the official text of the challenge:

On April 22, get outside, celebrate the planet and earn this award by doing any workout for 30 minutes or more. Record your time with the Workout app or any app that adds workouts to Health.

Apple has yet to announce the event officially, but details of it were unearthed this morning from the servers and shared in a tweet from Kyle Seth Gray. Apple will invite all Watch users to participate in this challenge by issuing a notification a few days ahead of the event.

This year’s Earth Day falls on Monday, April 22.