This is an exact analogue to the core ticket, JENKINS-9283, so I will copy the description here:

It would be nice if the cron expression took an optional timezone, this way I could schedule jobs in New York or the UK relative to them, rather than converting to central time. Also, since UK and the US observe daylight saving at different times, I have to adjust jobs an hour until both have converged

The solution would be to copy the logic from the original fix into some of these files.