How Hindu Calendar & Seasons – and how it relates to the calendar we use today?
Hindu Calendar, Panchangam – Time Measurement by Bharathiya People
Any Calendar is to measure time, to track seasons and to conduct festivals and celebrate important dates in a day to day life like birthday, marriage day etc.
Hindu Calendar  is based on lunar & solar movement. This calendar is used in Indian subcontinent, Cambodia, Malaysia, Laos and in many other places around the world.
Year or Samvat
Every calendar got a reference year to measure time, Present year is 2020 according to Christian or Pope Gregory of Catholic Church Calendar. This 2020 refers that these many years have passed after Jesus Christ. In Islamic Calendar the first year started with Prophet Mohammad (622 AD) and present year is 1442 for them. Similarly we got 3 reference points to measure number of years passed from a great event for us.
This reference is from the date of Shalivana or Saka Kingdom started ruling Bharath. This started from the year 78 AD of Christian Calender reference. The Present Year is 1942.
This year is with reference to Ujjain King Vikramaditya ruling of Bharath. This is 57 BC. So present Year is 2077.
This year is reference to Lord SriKrishna going to Vaikuntam leaving earth and starting of Kaliyuga. This year today is 5122.
Zodiac signs, stars, universe
If we look at the infinite universe from the earth, we see the planets and stars. We can draw the universe as a 360 degree circle around us by making our earth as center. If we make 12 slices of this circle, we get 12 signs, one zodiac is 30 degrees and 27 Nakshatra as 13.33 degrees pie.
The first 30 degrees are Aries, 60 is called Taurus, 150 is a Lion and 270 degrees are named Sagittarius.Similarly the first 13.33 degrees as Ashwini, 26.66, Bharani at 133.3, Makha at 266.6, Poorva-Ashada.
Look at these signs and stars in the picture below. Observe their degrees carefully. The earth is in the centre of the nucleus, and we are on it. Our calendar is built on this -Know more -www.raj.guru