The Baldwins are in Hollywood, and get bombed.
Then, in the next seen, South Park Elementary starts it's school day, and Mr. Garrison is complaining about having to chuck his lesson plan and teach theirs. Then he makes the periods (5 days bleed - no die) comment.
Then, they get called to the Gymnasium immediatly for a special announcement.
Then, Clinton comes on the TV, and says "At 5 am today, a day which will live in infamy, the Canadians have bombed the Baldwins. In response to this, the US has declared war on Canada"
If it happened as of 5 am California time, and the Baldwins were in California, the sun would not have been up. And it's clear from the scene that the sun is up and the Baldwins are lounging pool side.
If it happened as of 5 am Washington DC time, where Clinton made the announcement, then it would have been 2 am, and there is no way in hell the sun would have been up in California.