DNA: How is New Year of Hindu Panchang different from Gregorian Calender`s New Year?

The Gregorian calendar is based on the Earth's revolution as it revolves around the Sun, while the Hindu calendar is based on the motion of the Moon around the Earth. In the Gregorian calendar, there are 30 or 31 days in every 12 months, while according to the Hindu calendar the months are only 28 days.