Changes

The Manas, measures of time, which are used in daily activities are four in number - सौरचान्द्रार्क्षसावनैः । Solar, Lunar, Sidereal, and the Savana (Civil). The Mana of Jupiter (Barhaspatya) is used for determining the Shasthtyabda (60 Samvatsaras) or calculation of how a person attains 60 years of age. The remaining four Manas are not used for daily activities.<ref name=":1">Pt Mahavir Prasad Srivastav (1940 First Edition) ''Surya Siddhanta with Vijnana Bhashya, Parts 1 and 2.'' Allahabad: Dr. Ratnakumari Svadhyaya Sansthan. (Page 794 -)</ref>

The Manas, measures of time, which are used in daily activities are four in number - सौरचान्द्रार्क्षसावनैः । Solar, Lunar, Sidereal, and the Savana (Civil). The Mana of Jupiter (Barhaspatya) is used for determining the Shasthtyabda (60 Samvatsaras) or calculation of how a person attains 60 years of age. The remaining four Manas are not used for daily activities.<ref name=":1">Pt Mahavir Prasad Srivastav (1940 First Edition) ''Surya Siddhanta with Vijnana Bhashya, Parts 1 and 2.'' Allahabad: Dr. Ratnakumari Svadhyaya Sansthan. (Page 794 -)</ref>

While Suryasiddhanta is an astronomical text which is fundamentally a scientific treatise, Dharmashastra Nibandha texts such as Dharmasindhu and Nirnaya Sindhu also help us in determining the different Manas and lays down the vidhis associated with them. According to Dharmasindhu<blockquote>तत्र कालः षड्विधः ॥ वत्सरः अयनम् ऋतुर्मासः पक्षो दिवस इति॥ (Dharm. Sind.1)<ref name=":3">The Dharmasindhu by Kasinath Upadhyaya (1986 Reprint Edition) Delhi: Sri Satguru Publications (Pages 1-7)</ref></blockquote>Kala is of six kinds. Vatsara (वत्सरः) - one year, Ayanam (अयनम्) - half of a year or six months, Rtu (ऋतुः) - one season or two months, Masa (मासः) - one month or 30 days, Paksha (पक्षः) - one fortnight or 15 days, and Divasa (दिवसः) - one day.

While Suryasiddhanta is an astronomical text which is fundamentally a scientific treatise, Dharmashastra Nibandha texts such as Dharmasindhu and Nirnaya Sindhu also help us in determining the different Manas and lays down the vidhis associated with them. According to Dharmasindhu<blockquote>तत्र कालः षड्विधः ॥ वत्सरः अयनम् ऋतुर्मासः पक्षो दिवस इति॥ (Dharm. Sind.1)<ref name=":3">Vasudeva Sharma (1939) ''The Dharmasindhu by Kasinath Upadhyaya.'' Mumbai: Nirnaya Sagar Press (Pages 1-4)</ref></blockquote>Kala is of six kinds.  

 

# Vatsara (वत्सरः) - Year

# Ayanam (अयनम्) - half of a year or six months

# Rtu (ऋतुः) - one season or two months

# Masa (मासः) - one month or 30 days

# Paksha (पक्षः) - one fortnight or 15 days

# Divasa (दिवसः) - one day.

It may be noted that the six kinds of time mentioned in Dharmasindhu are discussed in Suryasiddhanta also.

It may be noted that the six kinds of time mentioned in Dharmasindhu are discussed in Suryasiddhanta also.

==== पितृपक्षम् ॥ Pitrpaksha ====

==== पितृपक्षम् ॥ Pitrpaksha ====

<blockquote>ततः शेषाणि कन्याया यान्य् अहानि तु षोडश । क्रतुभिस् तानि तुल्यानि पितृऋणाम् दत्तम् अक्षयम् ॥ (Sury. Siddh. 14.6)</blockquote>After the 4th Shadasheethi Mukha (in Kanya), the remaining 16 solar days of the solar month when Sun is in Kanya rashi are equivalent to the time of Yajna, (kala when any good actions give great merit) and in these days dana offered to Pitrs will give infinite merit.<ref>Pt. Bapu Deva Sastri (1861) ''Translation of the Surya Siddhanta and Revision of Siddhanta Siromani Translated by Lancelot Wilkinson.'' Calcutta: Asiatic Society. (Pages 91-)</ref>

<blockquote>ततः शेषाणि कन्याया यान्य् अहानि तु षोडश । क्रतुभिस् तानि तुल्यानि पितृऋणाम् दत्तम् अक्षयम् ॥ (Sury. Siddh. 14.6)</blockquote>After the 4th Shadasheethi Mukha (in Kanya), the remaining 16 solar days of the solar month when Sun is in Kanya rashi are equivalent to the time of Yajna, (kala when any good actions give great merit) and in these days dana offered to Pitrs will give infinite merit.<ref name=":4">Pt. Bapu Deva Sastri (1861) ''Translation of the Surya Siddhanta and Revision of Siddhanta Siromani Translated by Lancelot Wilkinson.'' Calcutta: Asiatic Society. (Pages 91-96)</ref>

From this we understand that, Shraddha for Pitrs should happen when Sun is in Kanya rashi starting from 15° to 30° according to Saura Mana. However, in the present times, Saura Mana is not used. According to Purnimanta system, Krishna paksha of Ashvini month (dark half of month of Ashvini) and according to Amanta system, Krishna paksha of Bhadrapada month (dark half of the month of Bhadrapada) i.e., calculated according to Chandra Mana are the days of Pitrpaksha followed by people.<ref name=":1" />

From this we understand that, Shraddha for Pitrs should happen when Sun is in Kanya rashi starting from 15° to 30° according to Saura Mana. However, in the present times, Saura Mana is not used. According to Purnimanta system, Krishna paksha of Ashvini month (dark half of month of Ashvini) and according to Amanta system, Krishna paksha of Bhadrapada month (dark half of the month of Bhadrapada) i.e., calculated according to Chandra Mana are the days of Pitrpaksha followed by people.<ref name=":1" />

==== सङ्क्रान्तयः ॥ Sankrantis ====

==== सङ्क्रान्तयः ॥ Sankrantis ====

[[File:Names of Sankrantis.PNG|thumb|474.556x474.556px|Names of 12 Sankrantis]]

[[File:Names of Sankrantis.PNG|thumb|Names of 12 Sankrantis]]

The time at which Sun enters into an new rashi is termed Sankranti. <blockquote>भचक्रनाभौ विषुवद्द्वितीयं समसूत्रगम् । अयनद्वितयं चैव चतस्रः प्रथितास्तु ताः॥ (Sury. Siddh. 14.7)</blockquote>In the middle of the nakshatra chakra (sphere of stars) the two equinoxes (Vishuvats in Mesha and Tula rashis) are diametrically opposed and so are the two solistices (Ayanas in Karkataka and Makara) in the ecliptic path.  

The time at which Sun enters into an new rashi is termed Sankranti. <blockquote>भचक्रनाभौ विषुवद्द्वितीयं समसूत्रगम् । अयनद्वितयं चैव चतस्रः प्रथितास्तु ताः॥ (Sury. Siddh. 14.7)</blockquote>In the middle of the nakshatra chakra (sphere of stars) the two equinoxes (Vishuvats in Mesha and Tula rashis) are diametrically opposed and so are the two solistices (Ayanas in Karkataka and Makara) in the ecliptic path.  

  '''1 Saura Dina (Solar Day) = Movement of Sun in a Rashi by 1° in ecliptic path'''

  '''1 Saura Dina (Solar Day) = Movement of Sun in a Rashi by 1° in ecliptic path'''

  '''1 Saura Masa (Solar Month) = Movement of the Sun across one Rashi (30°) in ecliptic path = 30.43803 days'''

  '''1 Saura Masa (Solar Month) = Movement of the Sun across one Rashi (30°) in ecliptic path = 30.43803 Savana Days'''

  '''1 Saura Varsha (Solar Year) = 365.25 Savana or Civil days'''

  '''1 Saura Varsha (Solar Year) = 365.25 Savana Days'''

== सावनमानम् ॥ Savana Mana ==

== सावनमानम् ॥ Savana Mana ==

<blockquote>उदयाद् उदयम् भानोः सावनम् तत् प्रकीर्त्यते । सावनानि स्युरेतानि यज्ञकालविधिस्तु तैः ॥ </blockquote><blockquote>सूतकादिपरिच्छेदो दिनमासाब्दपास्तथा । मध्यमा ग्रहभुक्तिस्च सावनेन प्रकीर्त्यते ॥ (Sury. Siddh. 14.18-19)<ref name=":0" /></blockquote>The duration between two successive risings of the Sun is called a Savana Dina or Civil Day.<ref name=":1" />

<blockquote>उदयाद् उदयम् भानोः सावनम् तत् प्रकीर्त्यते । सावनानि स्युरेतानि यज्ञकालविधिस्तु तैः ॥ </blockquote><blockquote>सूतकादिपरिच्छेदो दिनमासाब्दपास्तथा । मध्यमा ग्रहभुक्तिस्च सावनेन प्रकीर्त्यते ॥ (Sury. Siddh. 14.18-19)<ref name=":0" /></blockquote>The duration between two successive risings of the Sun is called a Savana Dina or Civil Day.<ref name=":1" />

Observations of sunrise over a very long time has revealed that the duration of a day is not constant but varies from day to day although very slightly. An average calculated based on the observations is referred to as the Mean Solar Day or Mean Civil day. Savana Dina is divided into 60 equal parts called Ghatikas or 24 equal parts called Hora (hours). Thus the 24 hour day that is used for our regular daily activities is the Savana Dina.<ref name=":2">Rao, S. Balachandra. (2000) ''Indian Astronomy, An Introduction.'' Hyderabad: Universities Press (India) Limited. (Page 39-50)</ref>

Observations of sunrise over a very long time has revealed that the duration of a day is not constant but varies from day to day although very slightly. An average calculated based on the observations is referred to as the Mean Solar Day or Mean Civil day. Savana Dina is divided into 60 equal parts called Ghatikas or 24 equal parts called Hora (hours). Thus the 24 hour day that is used for our regular daily activities is the Savana Dina.<ref name=":2">Rao, S. Balachandra. (2000) ''Indian Astronomy, An Introduction.'' Hyderabad: Universities Press (India) Limited. (Page 39-50)</ref> Based on Suryasiddhanta (1.12) 30 Savana days will form a Savana month.

  '''1 Savana Day (Civil Day) = 60 Ghatikas = 24 Hours'''

  '''1 Savana Day (Civil Day) = 60 Ghatikas = 24 Hours'''

==== Purpose of Savana Dina ====

==== Purpose of Savana Dina ====

# Savana days are used to determine the time of to perform yajnas.

# Savana days are used to determine the time of to perform yajnas.

# Determine [[Asoucha (आशौचम्)|Asoucha]] or Sutaka due to birth and death

# Determine [[Asoucha (आशौचम्)|Asoucha]] or Sutaka due to birth and death

# Limits of Chandraayana and other vratas

# Limits of Chandraayana and other vratas

# Determine the rulers of the day, month and year

# Determine the rulers of the day, month and year

# To calculate the mean motion of planets.

# To calculate the mean motion of planets.<ref name=":4" />

== चान्द्रमानम् ॥ Chandra Mana ==

== चान्द्रमानम् ॥ Chandra Mana ==

Dharmasindhu elaborates about the course of a lunar month, when the Moon goes through a cycle of phases, from new moon to full moon and then to new moon again. <blockquote>शुक्लप्रतिपदादिदर्शांन्तैश्चैत्रादिसंज्ञैर्द्वादशभिर्मासैश्चतुःपञ्चाशदधिकशतत्रयदिनैः सति मलमासे त्रयोदशभिर्मासैश्चान्द्रो वत्सरः॥ (Dhar. Sind. 1)<ref name=":3" /></blockquote>From the Shukla Pratipat tithi till the end of Amavasya, there are 30 tithis; together they constitute one Chandra-masa or Lunar month namely Chaitra, etc. 12 such Lunar months make up a Lunar Year having 354 days (savana days). When an Adhika masa is present there are 13 months a lunar year.

Dharmasindhu elaborates about the course of a lunar month, when the Moon goes through a cycle of phases, from new moon to full moon and then to new moon again. <blockquote>शुक्लप्रतिपदादिदर्शांन्तैश्चैत्रादिसंज्ञैर्द्वादशभिर्मासैश्चतुःपञ्चाशदधिकशतत्रयदिनैः सति मलमासे त्रयोदशभिर्मासैश्चान्द्रो वत्सरः॥ (Dhar. Sind. 1)<ref name=":3" /></blockquote>From the Shukla Pratipat tithi till the end of Amavasya, there are 30 tithis; together they constitute one Chandra-masa or Lunar month namely Chaitra, etc. 12 such Lunar months make up a Lunar Year having 354 days (savana days). When an Adhika masa is present there are 13 months a lunar year.

=== Purpose of Chandra Mana ===

=== Purpose of Chandra Mana ===

# Determination of Tithi, Karana (half of Tithi)

# Determination of Tithi, Karana (half of Tithi)

# Determine the auspicious time for samskaras like marriage

# Determine the auspicious time for samskaras like marriage

# Determine the appropriate time for activities such as shaving, tonsure

# Determine the appropriate time for activities such as shaving, tonsure

  '''1 Tithi (Lunar Day) = Time taken by the Moon to cover a distance of 12° relative to the Sun'''

  '''1 Tithi (Lunar Day) = Time taken by the Moon to cover a distance of 12° relative to the Sun'''

  '''1 Chandra Masa (Lunar Month) = 29.530589 days'''

  '''1 Chandra Masa (Lunar Month) = 29.530589 Savana Days'''

 

'''1 Chandra Varsha (Lunar Year) = 354 Sayana Days'''

== नाक्षत्रमानम् ॥ Nakshatra Mana ==

== नाक्षत्रमानम् ॥ Nakshatra Mana ==

=== नाक्षत्रदिनम् ॥ Nakshatra Dina (Sidereal Day) ===

=== नाक्षत्रदिनं नाक्षत्रमासं च॥ Nakshatra Dina and Masa (Sidereal Day and Month) ===

<blockquote>नाडी षष्ट्या तु नाक्षत्रमहोरात्रं प्रकीर्तितम् । तत्त्रिम्शता भवेन्मासः सावनोऽर्कोदयैःस्मृतः॥ (Sury. Siddh. 1.12)</blockquote>The time which contains sixty ghatikas is called a Nakshatra Ahoratra (a sidereal day and night) or Day and a Nakshatra masa (a sidereal month) consists of thirty Nakshatra Ahoratras. <blockquote>भचक्रभ्रमणम् नित्यम् नाक्षत्रम् दिनम् उच्यते। नक्षत्रनाम्ना मासास् तु ज्ञेयाः पर्वान्तयोगतः ॥ (Sury. Siddh. 14.15)<ref name=":0" /></blockquote>The time taken for one revolution of the sphere of stars is called a sidereal day. The time taken by the fixed stars to go around the earth is called a Nakshatra Dina or Sidereal Day; and this time is equal to the period of the rotation of the Earth.

<blockquote>नाडी षष्ट्या तु नाक्षत्रमहोरात्रं प्रकीर्तितम् । तत्त्रिम्शता भवेन्मासः सावनोऽर्कोदयैःस्मृतः॥ (Sury. Siddh. 1.12)</blockquote>The time which contains sixty ghatikas is called a Nakshatra Ahoratra (a sidereal day and night) or Day and a Nakshatra masa (a sidereal month) consists of thirty Nakshatra Ahoratras. <blockquote>भचक्रभ्रमणम् नित्यम् नाक्षत्रम् दिनम् उच्यते। नक्षत्रनाम्ना मासास् तु ज्ञेयाः पर्वान्तयोगतः ॥ (Sury. Siddh. 14.15)<ref name=":0" /></blockquote>The time taken for one revolution of the sphere of stars is called a sidereal day. The time taken by the fixed stars to go around the earth is called a Nakshatra Dina or Sidereal Day; and this time is equal to the period of the rotation of the Earth.

Sidereal is a term used to refer to stars. It is important to note that the time taken by the fixed stars to go round the Earth once is not the same as that taken by the Sun. While all the celestial bodies appear to move from the east to west due to the diurnal motion, the Sun would have moved from west to east along the ecliptic by about 1°, relative to the stars. Therefore, the fixed stars take a little less than 24 hours (mean civil day) to complete a rotation around the Earth. As a natural consequence if a particular star rises in the eastern horizon at a particular time today, it will rise about two hours earlier after 30 days, 4 hours earlier after 60 days, and so on.  

Sidereal is a term used to refer to stars. It is important to note that the time taken by the fixed stars to go round the Earth once is not the same as that taken by the Sun. While all the celestial bodies appear to move from the east to west due to the diurnal motion, the Sun would have moved from west to east along the ecliptic by about 1°, relative to the stars. Therefore, the fixed stars take a little less than 24 hours (mean civil day) to complete a rotation around the Earth. As a natural consequence if a particular star rises in the eastern horizon at a particular time today, it will rise about two hours earlier after 30 days, 4 hours earlier after 60 days, and so on.  

It is found that the fixed stars take about 3 minutes 56 seconds less than the Sun to go round the Earth once.  

It is found that the fixed stars take about 3 minutes 56 seconds less than the Sun to go round the Earth once.  

  '''1 Nakshatra Dina = 60 Ghatikas'''

  '''1 Nakshatra Dina = 60 Ghatikas'''

  '''1 Nakshatra Day = 1 Savana Dina - 3 mins 56 secs = 23 Hrs 56 Mins 4 Secs'''

  '''1 Nakshatra Day = 1 Savana Dina minus 3 mins 56 secs = 23 Hrs 56 Mins 4 Secs'''

 

 

'''1 Nakshatra Varsha = 12 Nakshatra Masas'''

==== Purpose of Nakshatra Dina ====

=== Purpose of Nakshatra Dina ===

# Naming of lunar months is from the Nakshatras; the name of a lunar month is determined from the nakshatra in which moon is present at the time of Purnima (15th day of full moon) tithi (with a few exceptions).  

# Naming of lunar months is from the Nakshatras; the name of a lunar month is determined from the nakshatra in which moon is present at the time of Purnima (15th day of full moon) tithi (with a few exceptions).  

=== Summary ===

=== Summary ===

  1 Saura Dina (Solar Day) = Movement of Sun in the Rashi by 1 degree

  '''1 Saura Dina (Solar Day) = Movement of Sun in the Rashi by 1 degree'''

  1 Tithi (Lunar Day) = Movement of Moon by 12 degrees

  '''1 Tithi (Lunar Day) = Movement of Moon by 12 degrees'''

  1 Savana Dina (Civil Day) = 24 hours

  '''1 Savana Dina (Civil Day) = 24 hours'''

  1 Nakshatra Dina (Sidereal Day) = 23 Hrs 56 Mins 4 Secs

  '''1 Nakshatra Dina (Sidereal Day) = 23 Hrs 56 Mins 4 Secs'''

== Four Other Manas ==

== Four Other Manas ==

# Determine the Masikas (performing monthly Pitr kriyas upto one year of death).

# Determine the Masikas (performing monthly Pitr kriyas upto one year of death).

# Determine the time of annual Shraddha

# Determine the time of annual Shraddha

== References ==

== References ==

[[Category:Vedangas]]

[[Category:Vedangas]]

<references />

<references />