As of 4:48 AM EDT, the Geometry Dash servers are currently down. This is so that they can migrate to stronger servers before update 2.2.
While RobTop Games originally said the server migration should take 6 hours, he has now said it could take upwards of 10 hours.
With this, you can expect the Geometry Dash servers to be back up by 4:00 PM EDT.
RobTop has confirmed that Geometry Dash 2.2 will not be releasing today or tomorrow because of the server downtime. However, we can still expect update 2.2 this month, but there is a small chance that update 2.2 will be delayed until November.