Verified answer

Conductors do indicate the time of the music, but they also use their hands, facial expressions, and movement of their bodies in order to get the musicians to interpret the music in a particular way.

As far as keeping strict time (which you will never see in an orchestra, though you will in a marching band), it depends on what time signature the music is in. However, beat one is always down, the second to last beat is always on the right, and the last beat is always up.

So in a basic 4/4 pattern, it would be down, left, right, up. 3/4 would be down, right, up. 2/4 would be just down and up. More complicated time signatures have more complicated patterns.