In Taiwan, Father's Day is not an official holiday, but is widely observed on August 8, the eighth day of the eighth month of the year.
In Mandarin Chinese, the pronunciation of the number 8 is bā. This pronunciation is very similar to the character "爸" "bà", which means "Papa" or "father". The Taiwanese, therefore, usually call August 8 by its nickname, "Bābā Holiday" (爸爸節). (wikipedia)
Father's Day is a celebration honoring fathers and celebrating fatherhood, paternal bonds, and the influence of fathers in society. It is celebrated on the third Sunday of June in many countries and on other days elsewhere. It complements Mother's Day, the celebration honoring mothers.
In most countries Father's Day is marked on the third Sunday of June:
Argentina, Britain, Venezuela, Ecuador, Zimbabwe, India, Ireland, Canada, China (including Hong Kong and Macau), Colombia, Costa Rica, Cuba, Malaysia, Malta , Mexico, Pakistan, Panama, Peru, Philippines, Singapore, Slovakia, USA, Turkey, France, Holland, Chile, Switzerland, South Africa, Japan.
Countries that celebrate other dates (in alphabetical order):
Austria: second Sunday of June;
Australia: the first Sunday of September;
Belgium: St. Joseph - (March 19) and the second Sunday of June (secular);
Brazil: second Sunday of August;
Bulgaria: December 26;
Germany: Ascension Day;
Denmark: June 5 (also Constitution Day);
Dominican Republic: last Sunday of July;
Estonia: second Sunday of November;
Spain: March 19;
Italy: March 19;
Lithuania: first Sunday of June;
New Zealand: the first Sunday of September;
Nicaragua: June 23;
Norway: second Sunday of November;
Poland: June 23;
Portugal: March 19;
Russia: February 23 (Day of Defender of the Fatherland, a military celebration, considered by many to be the day of her husband);
Thailand: December 5 (the birthday of King Bhumibol Adulyadedzh);
Taiwan: August 8;
Finland: the second Sunday of November;
Sweden: second Sunday of November;
South Korea: May 8 (Parents Day).
An interesting Flash Mob for the Father's Day (June 2011)