The birth of Siddhartha Gautama, Attainment of Buddha-hood, and Parinirvana (session of life) all happened in the Vesak Full Moon Poya (Purnima) day. It is the first full moon of May. That is the most holy day for Buddhists.
Secondly, the Full Moon day of June is important to Buddhists in Sri Lanka. The son of Ahoka Empire Mihindu Maha Thero, a Buddhist Monk came to Sri Lanka and officially introduced Buddhism to Sri Lanka. The Sri Lankan King Devanampiyatissa became a Buddhist this day.
Thirdly, the Full Moon day of July is also important to Buddhists in Sri Lanka. The daughter of Ashoka Empire, Sanghamitta Maha Teri, a Buddhist nun brought the Jaya Sri Maha Bodhi Tree to Sri Lanka, a sapling from the Bodhi tree under which Siddhartha attained the Buddha-hood. That is the oldest known tree still living in Anuradhapura Sri Lanka.
The Holy building for Buddhists is called a Temple.
Buddhists celebrate many holy days throughout the year. The Buddhist New Year, Dhamma Day, the Elephant Festival, Ancestor Day and Veska are just a few.
While Buddhists have many special days and celebrations during the year these are not correctly called "holy" days as Buddhism has no deity (a prerequisite for being a holy anything.) Buddhist festivals celebrate special events in the Buddha's life and underscore important teachings As far as an equivalent to the Cristian's Sunday, the Jewish Saturday or the Muslim Friday - no such weekly observation is specified in Buddhist tradition.
There is no specific day of the week. Instead, the holy days or "days of rest" are connected to the lunar cycle. Which I believe are full, new and the two halfs meaning that there are still four days a month but are not connected to week days.
Buddhists worship in a 'pagoda.'
tripitaka
the Tripitaka
Jews, Christians and Muslims. Maybe some Hindus too. And a couple Buddhists. Let's not forget the Buddhists.
Yes, at home and also at a temple.
Buddhists do not go to mass. Only Christians and Catholics do.
Buddhists do not worship the Ganges, or any other thing or deity. Hindus believe that the Ganges is holy, but since I am not a Hindu I can not tell you why.
For Buddhists the Tripitaka, or Three Baskets are the primary teachings. for Hinduism the Vedas and the Upanishads are their sacred texts. For Sikhs their holy book is the Holy Granth