This should come as no surprise, because I don't think Google ever had a special Doodle or logo for the President's Day holiday. Today is no different, Google.com in the US is bare, with a simple Google ordinary logo. There is no mention of the US national holiday, President's Day on Google whatsoever.
That doesn't mean other search engines aren't making a mention of the holiday.
Yahoo has an animated logo for the day:
Bing has a nice theme with Mount Rushmore:
Ask.com has a nice theme as well:
Dogpile is going with the Winter Olympics right now.
Forum discussion at Google Web Search Help.