If the center of gravity for those two objects is (xc,yc) and the supporting point is (x,y)
The conditions for stable equilibrium is (x=xc and y>yc) when supporting bar is horizontal.

The who system can be model like a pendulum, the supporting point is the tip of the pendulum, and assume all the mass is located at the center of the gravity.

For the time offset:
Please click the [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=profile]PROFILE[/url] link,
then click [b]Look and Layout Preferences[/b] from the left menu.
You will find "Time Offset:" in the table,  change the value from 0 to 1 (or click auto detect link)
then click [b]Change Profile[/b] button , then everything should be fine for your time format.