Oh, much more than that. You need to memorise the layouts of all 16 timezones and be able to flip them upside down and left to right in your head
Truly wonderful game though. When I was about 15 I spent a large percentage of my waking hours over an entire summer holiday playing one game a day of this trying to beat my high score. Got up to about 300k points. A few years back I spent a few weeks re-learning it and then managed to push my score up to about 450k, although the Automation crack looks to have a bug in it that costs at least 15k points (and, concomittantly, 15 extra lives).