Let us understand more about this calendar with the help of a model.
In earlier videos, we explored key events associated with the Sun, Earth and Moon.
Relative locations were discussed as per Gregorian calendar as well as Hindu Calendar.
In this video, let us explore one more calendar, India’s National Solar calendar.
We will focus on the movement of Earth and Sun during a span of one year and arrangement of months related to the same.
Months of Gregorian calendar are listed on the outer rim like this.
January, February, March, April and so on …
Unlike the Luni-solar based Hindu Calendar, the National Solar Calendar is based on the movement of Earth around the SUN.
1st day of this calendar starts on the Vernal Equinox, when days and nights are equal.
This day happens to be the 22nd March of the Gregorian Calendar.
There are twelve months of the National Solar Calendar.
They are named as
Chaitra,
Vaishakh
Jeshtya
Aashadh
Shravan
Bhadra
Ashwin
Kartik
Agrahayan
Paush
Magh
Falgun.
First month of Chaitra has 30 days while the next five months marked in Green have 31 days.
Remaining months marked in yellow are 30 days each.
Each month has a fixed start date associated with the Gregorian calendar.
Chaitra starts on 22nd March.
Vaishakh starts on 21st april
Jeshtya starts on 22 May
Aashadh starts on 22 June
Shravan starts on 23 July
Bhadrapad starts on 23 August
Ashwin starts on 23 Sept
Kartik starts on 23 Oct
Instead of Margshirsh, this month is called Agrahayan and starts on 22 Nov
Paush starts on 22 Dec
Magh on 21st Jan
And Falgun on 20th Feb.
All months together account for 365 days.
When there is a leap year. Chaitra has 31 days instead of 30 and starts on 21st March of Gregorian Calendar.
Sun spends more time in the Northern Hemisphere hence these months are 31 days each.
Now let us view the position of Earth’s axis from the front side.
On 21st March, Start of Chaitra month, both hemisphere receive equal amount of light. - Equinox.
On 22nd June, Earth’s axis is tilted towards the sun. Days are longer and nights shorter in Northern Hemisphere. This day is also the first day of Aashadh.
Dakshinayan starts from this date as well.
On 23rd September there is another equinox. This is also the start of Ashwin Month.
On 22nd December, Earth’s axis is tilted away from the SUN. This is also the start of Paush month.
How about seasons.
National solar calendar has identified six seasons associated with 2 months each.
Grishma - Summary - Vaishakh and Jeshtya
Varsha - Rainy Season - Aashadh and Shravan
Sharat - Autumn - Bhadra and Ashwin
Hemant - Kartik and Margashirsh or Agrahayan
Shishir - Winter - Paush and Maagh
Vasanta - Spring - Falgun and Chaitra.
Sun spends more time in Northern Hemisphere than Southern Hemisphere. hence these months have 31 days
Sequence of the year is as per the Shalivahan Shak.
More information is available on the website https://www.rdpm.in/ as well.
