On March 18, 2018, Hindus around the world are celebrating the new year. The new Hindu year – Vikram samvat-began 57 years before the Christian Era- established by the great king of Ujjain, who defeated the enemies of the country- and wore the title of Vikramaditya.
Though for all practical purposes, Hindus follow the Gregorian Calendar in offices but every festival, birth and death rituals, marriages take place according to Hindu calendar system. We all are lucky because this system is still alive after western colonizers who did their best to remove our rich traditions from our memories.
Westerns did not have any calendar till very recently. they practiced a ten-month year system, completely forgetting the three months of the winter. When the western world was busy in declaring women as witches and having no soul, and a Galileo was hanged for declaring scientific facts, Indians scientists were giving the world the gifts of science and mathematics- they gave zero, measured the circumference of the earth, gave astronomy, named galaxy, stars, months, and orbits, when there were no telescopes. Arybhatta refined the Hindu calendar as early as 5th Century.
In Indian calendar system when full moon month cycle was followed, the 12 lunar months made a year of about 355 days. So, after every two and half years a lunar month (of 29.53 days) was added. Thus, an average year contained 366 days (i.e. one day extra). This anomaly was rectified by dropping a month after every 30th year (30 solar years @ 365.24219 days = 10957 days; 371 lunar months @ 29.53059 days = 10956 days). The concept of dropping a month was there around 3000 BC and was carried to later period. Even then a small error of 5 lunar dates (tithes) was estimated in 90 years. Therefore, a special 5-year period was added with one extra date each year after 90 years.
Hindu new year is celebrated not only in India but also in Nepal, Indonesia, Cambodia. Vikram samvat is official calendar of Nepal.