Today's celebrations (actually yesterday's)

April 14th has a bunch of celebrations to consider:

National Pecan Day * ^
Look up at the Sky Day
Reach as High as You Can Day 
International Moment of Laughter Day
Children With Alopecia Day (overall hair loss)
National D.A.R.E Day
Pan-American Day
Ex Spouse Day

President Abraham Lincoln is shot by John Wilkes Booth at Ford's Theater in Washington, D.C., 1865 (He died the next day) 

Christian Feast Day: Bénézet, Domnina of Terni, Lidwina, Peter González
St. Tiburtius' Day
Day of Mologa (Yaroslavl Oblast, Russia)
N'Ko Alphabet Day (Mande speakers)
Ambedkar Jayanti (India)
Black Day (South Korea)
Youth Day (Angola)
Dia De Las Americas (Honduras)
Vaisakhi (India)
Cultural Unity Day, recognized by India, Sri Lanka, Maldives, Bangladesh and Nepal

New Year festivals in South and Southeast Asian cultures, celebrated on the sidereal vernal equinox: ^
-Assamese New Year, or Rongali Bihu (India's Assam Valley)
-Bengali New Year, or Pohela Boishakh (Bangladesh and India's West Bengal state)
-Burmese New Year, or Thingyan (Burma)
-Hindu and Sikh New Year, or Vaisakhi (Punjab region)
-Khmer New Year, or Chol Chnam Thmey, most commonly celebrated on April 13 (Cambodia)
-Lao New Year, or Songkan / Pi Mai Lao, generally celebrated from 13 to 15 April (Laos)
-Malayali New Year, or Vishu (India's Kerala state)
-Nepali New Year, or Bikram Samwat / Vaishak Ek (Nepal)
-Oriya New Year, or Maha Visuba Sankranthi (India's Orissa state)
-Sinhalese New Year, or Aluth Avurudhu (Sri Lanka)
-Tamil New Year, or Puthandu (India's Tamil Nadu state)
-Thai New Year, or Songkran, celebrated from 13 to 15 April (Thailand)
-Tuluva New Year, or Bisu (India's Karnataka state)
-The first day of Takayama Spring Festival (Takayama)

(* in posts, previously or to follow)

(^ Photo credits: candiedpecans.net; Team Singapore fireworks display from Singapore Fireworks Festival 2006, Wikipedia)