Yesterday, September 13, was the day OnePlus celebrated an important milestone in the company’s history: 1,500 days of OxygenOS. So between September 13 and today, September 14, for every tweet with the hashtag #OxygenOS, OnePlus is going to plant a tree.

The company has teamed up with WWF India to achieve this. It can be any tweet, not just a standard, and the company will count the hashtags today, September 14. Only tweets will be counted, so don’t retweet, in order for your hashtag to count.

There could be no better way to mark 1500 days of OxygenOS. We hope you like our initiative and energetically participate in doing your bit for nature. Tweet for trees, let’s make more Oxygen! — OnePlus

The actual process of planting trees will be, like the roll-out of OxygenOS updates, staged. “Each phase will have a limited capacity wrt the number of trees that can be planted”, the company says.