Algodoo

This pendulum swings once every approximately 1.00897 seconds (its period is 2.01796 seconds).

It is possible to make a more accurate pendulum, but the graph only shows either 1.01 or 0.98 seconds for the time of the first swing; in order to make a more accurate pendulum, you would have to allow it to swing for multiple seconds and calculate its frequency manually, needing to observe the pendulum for longer and longer depending on the accuracy you want.

When used in a clock, this pendulum is ahead by approximately 12 minutes and 55.8 seconds more each day.