All dates/times are stored "as is" and theres no timezone allowance made. ONLY when synchronising are timezones taken into account and thats purely to see which update took place first i.e. to see who whens in an update conflict.
So your system is working as designed. You get your people to book in the time as if they were in that zone i.e. if someone says I want a 9am meeting, put it in at 9am, dont think about timezones.
