Here are some completely made-up and utterly unconvincing excuses for not attending:
Random Excuse Generator My pet chicken had a sudden case of the fowl plague. My car broke down in a ditch, and I have to wait for a tow truck to arrive. I'm on a secret mission for the government, and I'm not allowed to reveal my location at this time. I accidentally superglued my shoes to the floor, and I'm still waiting for the janitor to come and scrape them off. I'm allergic to mornings. I'm on my way to a meeting of the world's most exclusive club, and I have to be there at 9:00 AM sharp. I'm a professional snail trainer, and I have to be in the lab by 8:00 AM to train my snails for the big competition.