One billion people used Facebook on Monday 24th August

"We just passed an important milestone. For the first time ever, one billion people used Facebook in a single day.
On Monday, 1 in 7 people on Earth used Facebook to connect with their friends and family.
When we talk about our financials, we use average numbers, but this is different. This was the first time we reached this milestone, and it's just the beginning of connecting the whole world.
I'm so proud of our community for the progress we've made. Our community stands for giving every person a voice, for promoting understanding and for including everyone in the opportunities of our modern world.
A more open and connected world is a better world. It brings stronger relationships with those you love, a stronger economy with more opportunities, and a stronger society that reflects all of our values.
Thank you for being part of our community and for everything you've done to help us reach this milestone. I’m looking forward to seeing what we accomplish together."
Source:  Facebook post by Mark Zuckerberg, 27th August 2015