wtf is wrong with people who don't understand time zones?

i constantly get business calls on my cell at odd hours. they know business hours are from 8am-4:30pm...like just now and it's 6:30am. i've gotten calls at 4am before also. the callers know i'm on the west coast of canada...would you people in the east get your shit together and learn time zones and just wait a few hours before calling?