[It] 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).She probably posted the greeting yesterday because Taiwan is about 13 hours ahead of us, so our August 7 was already their August 8.
Happy Father's Day in Taiwan!
Last night, a Taiwanese friend on Facebook posted "Happy Father's Day", so I did an online search to see why she would say that. It turns out that today (August 8) is Father's Day in Taiwan, and here's a good explanation about what it means: