Then why change it Fred, just to accomodate trackwork jockeys?
I'm sure you'd find most jockeys would jump at the chance just to ride Northerly in trackwork no matter what time of day it was.

Most people don't realise that the only reason horses are worked at around 4am in the morning, is because of trainer and jockey raceday committments.

I often make it a habit when travelling different timezones NOT to adjust my watch.
Why get jetlag unless it's absolutely necessary.