I used to tell the truth..just on principal. "If I want to take my kid out, I'll take them out and I don't need to lie about it." Then when I told the teachers early, they and just about everyone else at the school would "nudge, nudge, wink, wink " me and basically tell me to say they were sick. They want their funding, it is much easier for eveyone if you LIE LIE LIE.....
So since I dont' want to LIE to the teacher, I write..."To whom it may concern..." on their excuse, then it's not a lie to the teacher..
Check out my tag (self) in my avatar..I live in such a gray area, I can rationalize anything!