Click the green flag. This project tells you the milliseconds since the beginning of the first day of 1970 in Universal time. This may seem like a pretty random point in time to count from, but it is the way computers store time. (It still is pretty random, but it has been made significant)
You can get an HTML version of this counter! Simply click "See inside", show the hidden list, and export it! Make sure to save it as a .html file and you will be able to open it with a browser! The reason this project's ID is so low (104714413) is because I just edited my oldest unshared project because I thought it would be fun to have a lower ID than new projects.