Most of the Indian social and religious festivals are celebrated based on tithi . Even after migration to overseas countries, Indians living overseas would still celebrate their festivals on the same dates as Indians in India would. I m hundred percent with them. However, the intention here is provide the information for those who want to understand the importance behind the tithi on which Indian festivals are based. Calendar date that we are so familiar with in our daily life is based on solar calendar.
English calendar is a solar calendar.
The basis for solar calendar is the rotation of the Earth around the Sun. It takes earth approximately 365 days to complete its rotation around the Sun. The English calendar that most of us use today divides the 365 days of earth s period of rotation around the Sun in twelve months. The leap year, which occurs once every four years, accounts for day per year. Similar to solar calendar lunar calendar is also popular and widely used in the Asian countries such as China, Pacific-rim countries, Middle East countries, and India.