time zones.....

ok, so my fascination with my sitemeter continues.........i am currently perplexed as to how viewers can change time zones overnight.........most often it is central time zone in the evening.......and by morning the same reader will be eastern time zone........and this same reader has been both windows xp and mac within a few hours but with the same internet address.........which essentially leads me to doubt the accuracy of any of the information provided by the sitemeter service.......ah well........at least somebody reads it.........even if under mysterious circumstances........