1 April Fool's Day
1 International Tatting Day
3 National Walk to Work Day 1st Friday
5 Palm Sunday
5 World Youth Day date varies widely
10 Good Friday
12 Easter Sunday
15 Income taxes due
19 Passover begins at sundown, lasts 8 days.
20 Patriot's Day Third Monday
22 Earth Day (U.S.)
22 Administrative Professionals Day formerly "Secretaries Day"
23 Take Your Daughter to Work Day 4th Thursday
I got this info from http://www.holidayinsights.com/, if you want to know more info about April go check it out.