Silence Day is the name the followers of Indian spiritual master Meher Baba give to their practice of commemorating July 10 of each year by maintaining verbal silence for twenty-four hours.

From July 10, 1925 until his death in 1969, Meher Baba was silent.He communicated first by using an alphabet board, and later by hand gestures which were interpreted and spoken out by one of his mandali (devoted disciples), usually by his disciple Eruch Jessawala. For many years, Baba asked his followers to undertake various austerities on this date. In addition to keeping silence, Baba sometimes asked his followers to fast, to pray, to repeat the names of God, and similar practices. In his last request to his followers on the subject, in 1968, he asked only that they observe silence.

While Meher Baba did not establish any ongoing requirement, even after his death the majority of his followers voluntarily keep silent on July 10.

About his silence Meher Baba wrote:

Man’s inability to live God’s words makes the Avatar’s teaching a mockery. Instead of practicing the compassion he taught, man has waged wars in his name. Instead of living the humility, purity, and truth of his words, man has given way to hatred, greed, and violence. Because man has been deaf to the principles and precepts laid down by God in the past, in this present Avataric form, I observe silence.”

 

source Wikipedia