My much belated 2004 calendar question!
 

why are there random dates highlighted in red? I know it has every Sunday in red, but then there are other dates for which I don't think there's a holiday. On the current page, September has Monday the 20th and Thursday the 23rd highlighted; October has Monday the 11th.

Are these Japanese holidays? Or subliminal messages from Ayu?

Yeah, I think that they are Japanese holidays. I know for sure that October 11 is Sports Day, but I am unsure of the ones in September. One is probably Moon Viewing Day, but I thought that it was on the 28th. The 23rd might to highlighted for the first day of fall (although most calendars say that it was 22nd-- my Japanese teacher disagreed and said it was the 23rd).