I once took some modern dance lessons, that emphasized that the beat is when you finish a move.

E.g., if you step, your foot begins moving before the beat, but touches down on the beat. If you jump, it is when you touch down to land. Etc.

(Don't know if that applies to other land-dance forms, or even if it was just one instructor's standard.)

I've been looking at various videos on the web to see if there is a similar standard for ice skating (especially ice dance).

Since dance and pairs requires synchronization between skaters, I would expect there to be a clear standard.

I'm surprised to see very little agreement. When some people are doing basic skating strokes, as well as crossovers and progressives, they start moving on the beat, others touch down on the beat, others finish their extensions on the beat. I went back to youtube segments of Torvill and Dean, figuring they sort of created the ice dance standard, but they weren't consistent either.

I think skaters (non ice-dance here, since ice dancing doesn't involve many jumps) mostly take off on the beat, rather than land it. On lifts, it is all over the place.

So, for those of you who know how skating is judged, is there supposed to be a standard? What is it?

The only answer I can think of is that there are no beats in skating. Figure skating is not a rhythm-driven way of motion. There are elements of it that have a cadence, such as crossovers, but these cadences can be altered or even broken to fit a skater's technique and artistic expression.

The closest you will get to movement on the beat is compulsory dances. And even then, skaters can start on an "off-beat" and still be considered on time with the music.

Actually you'll get a deduction if you start on the weak beat in compulsories.

My coach wants the beat to fall on the finished extension, so he wants the foot to hit the ice the slightest, teensiest, tiniest bit ahead of the actual beat. This is for compulsory dance.