Shabad Kirtan: “Sawan Aaya He Sakhi ” byBhai Jasbir Singh Ji Paunta Sahib Wale.   Thank you Ji for the wonderful shabad.  (Source: deramithatiwana on YouTube)

By Harnaak Singh

We will now continue with the study of calendars.  We will review the major problems faced with the present calendar system used in the Sikh Panth to mark our religious events.

We will continue with the figure number from Part 5.  We use the Jagannath Hora for sidereal method of determining planetary positions and the Star Fisher for tropical method.  

The software we will use in ensuing analysis are Star Fisher and Jagannath Hora.  These programs are available for free download at





We live on the planet earth.  Our star is the SUN which is the source of our energy and hence our survival.  The moon is a permanent satellite of earth.  

Since our interest is the calendar, we shall focus on events and the timing and marking of events.  Event means a happening, for example birthday, examination day, wedding day etc.  The event will occur at a certain time.  That time is the event marker.  For example the examination will be at 9:00 am on 25-Apr-2018, the event is exam and the event marker is 9:00 am on 25-Apr-2018.  In this article we will refer to events and event markers. 

Note that all dates used in the article are Gregorian unless otherwise stated and the planetary positions are based on Amritsar, India.


Natural markers 

Both the sun and moon can be used as event markers.  The position/status of the sun or moon is the event marker.  For example midday, sunset, sunrise, phases of the moon.  To visually mark events using the sun is less practical.  Easily observable are the sunrise, sunset and midday and that too during the same day.  Between days there is no simple visually observable difference.  

However, the moon has more observable possibilities, new moon, full moon and quarter and three quarter moon and phases in between are possible event markers.  So using the moon to mark events gives us a better range.  

Essentially we use the planets position (e.g sunrise, sunset) and/or state (e.g. full moon, half moon) to mark events.  

We have seen how the moon is used as an events marker and has a bigger range of possibilities of marking events.  This is one of the reasons that the people of early times found it convenient to mark events using the moon phases or number of days in relation to the major moon phases of new moon and full moon.  

We can say that the rotation of the moon round the earth is why we can use the moon as an events marker.  One rotation of the moon around the earth is one lunar month.

Similarly, the earth rotates around the sun and one complete revolution, which we call a year, is another event marker.  This is generally termed the solar year.  

In addition to this the earth rotates on its own axis.  This rotation, which we call a day, is another event marker.

So far, all the above are God made event markers.  Essentially we are using these planetary bodies as a template to mark events e.g. the position of the sun was at “so and so place” or the moon at “so and so place” when “so and so” came to meet me.

Let us term these NATURAL event markers.  The position of these in the heavens (e.g. 0 degrees Aries) is used as the event marker.  The NATURAL markers are inherently accurate markers but they are generally difficult to determine; the calculations are very complex.  Figure 35 presents some pages from a document that gives planetary position calculations.  Note that Figure 35 shows only THREE equations (1), (2), and (3) on Page 1.  In the document there are many more equations.  So you can imagine the complexity of the calculations.

Figure 35: Extracts from document on planetary calculations

35 Planet Calc

LUCKILY for us the Star Fisher and the Jagannath Hora programs perform these calculations and help to easily determine the position of the planets of interest to us.

One important point to stress here is that the planets position must be determined with the location of the event as the reference.  For example if we want to mark events on the earth, then we must use EARTH as a reference.  Further if we want to mark the event, say at Amritsar, then we must use Amritsar as the location of reference.  We cannot use the STARS as a reference to mark events on earth.  

The TROPICAL method of positioning planets uses EARTH as reference BUT the SIDEREAL method of positioning planets uses the STARS as a reference.  So to mark events on earth, the tropical method is the appropriate method.  

This becomes evident in the following when we show that events marked with the sidereal method drifts due to the phenomenon of precession. 

Man-made markers

We have divided the day into hours, minutes, seconds etc so we can use man made devices to mark events within a day.  We use numbers to mark days in a year, 7 days to mark a week, divide the year into months and allocate number of days to the month.  This gives us the ability to mark events at any point of time using event markers.

These are all man made markers and let us term these MAN-MADE event markers.  BUT one important thing to note is that the MAN-MADE event markers are referenced to the NATURAL event markers.  For example Spring Equinox occurs when the earth’s axis plane is not inclined to the line between the sun and earth.  See Figure 36.  

In position 1 and 3 the earth axis is not inclined to the earth-sun line and in positions 2 and 4 the earth’s axis is inclined to the earth-sun line.  Position 1 is the Spring Equinox (or Vernal Equinox).

Figure 36: Earth axis in relation to sun

36 seasons copy

The MAN-MADE markers use the NATURAL markers as a reference.   This enables the MAN-MADE markers to mark events correctly within the limits of error.  Then our events can be referenced to the MAN-MADE markers.  

The MAN-MADE markers are much easier to use as compared to the NATURAL markers.  

For example “20th March” makes more sense than “Sun at 0 deg Aries” (which by the way means the same thing).  Figure 37 illustrates this.

Figure 37: MAN-MADE and NATURAL event markers for 20-March-2018

37 man made n natural marker

Notice that for all these event markers, we are using the earth as reference.  We are on this earth (most of us most of the time) so we must use the earth as a reference when we want to fix the MAN-MADE marker by referencing to the NATURAL markers.

In Figure 36 on SPRING EQUINOX, the Sun is at 0 deg Aries.  This is used as the REFERENCE to mark the date 20th March and this then fixes the MAN-MADE marker to correctly mark events to the NATURAL markers.  

All these, NATURAL and MAN-MADE, event markers are a template on which we place the event.


The major problem is the drift of the MAN-MADE dates as compared to the NATURAL reference.

Let us understand this problem.

One solar year is 365.24219 days.  However we can only have days in whole numbers, 365 or 366 days in a year.  

So if we say a year is 365 days a year, and if start counting from today, 365 days later we will have completed one year.  

Is this one year? No, we are 0.24219 days short.

On the other hand if we say that a year is 366 days, then we will have exceeded by 0.75781 days.

Now you see the problem.  This is where the leap year adjustment comes in.  This leap year adjustment had been discussed in Part 1.  Please review Part 1 to understand this.

Different calendar systems have different leap year adjustment rules.  

What is happening, due to this inherent “whole day” problem is, as time goes on the accuracy starts to drift from the actual, so the rule is used to bring the date in line with the actual based on planetary positions.  This is what the leap year adjustment is doing.

Gregorian and Julain Calendar – leap year adjustment

We will repeat the figure previously used which shows the Gregorian leap year rule applied as well as what happened to the Julian year which had a different leap year adjustment rule.

Figure 38: Leap year adjustment for Gregorian calendar

38 Gregorian accuracy copy

Note that the Julian year keeps drifting (shown by dashed lines in Figure 38) from the spring equinox as time goes on. 

However, the additional “century adjustment” (green text in Figure 38) in Gregorian year leap year adjustment brings it back to the summer equinox reference point giving it better accuracy than the Julian calendar.  

In the Julian calendar the dates were drifting causing problems with planning for seasons and religious activities which were marked by planetary positions.

This was the reason for change to the Gregorian calendar.

Notice that the maximum drift in the Gregorian case is just over 1 day which occurred on the day following February 28 in the leap year 1900 and will occur again in 2100 (see Figure 38).

Lunar calendar – Intercalary month adjustment  

We have seen the intercalary month adjustment in the lunar month (in Parts 4 and 5) to bring it back in line with the solar year.  This is sort of an adjustment rule similar to the leap year adjustment.  Figure 39 shows the concept behind this adjustment.

Figure 39: Leap adjustment of the lunar year with an intercalary month addition

39 Intercalary 2004 copy

The example in Figure 39 shows the correction in the lunar month SAVAN in 2004.  This adjustment is done in the range every 2 year 4 months to 2 year 11 months.  

The maximum drift can be up to 29 days when this adjustment is done.  For example in Figure 38 this drift is 29 days, Sangrand Phadron started on 16-August but lunar Phadron started on 14-September.  Fairly large variations are expected to occur yearly.

Notice the drift with the lunar calendar can be up to 29 days as compared to the drift of about 1 day in the Gregorian calendar.

Sidereal solar calendar

We have seen that the Sidereal based calendar e.g. the Hindu solar calendar is drifting due to precession which we have discussed in the previous parts.  The Sikh Panth uses the sidereal calculation to mark the Sangrand days (in our series of articles we use the Jagannath Hora). This drift is shown with reference to the SPRING EQUINOX, which remains fixed in the tropical calculations (using Star Fisher).  These two systems, sidereal and tropical coincided in 285 CE.  This drift is shown in the table below with the start date of ARIES (which should signal CHET but presently CHET is signaled by PISCES – see comments below) in the Gregorian calendar as reference.  Note that we know that the start date of ARIES using the tropical calculation does not drift within limits of the leap year adjustment.   

285 CE 20th March   20th March
1285 CE 2nd April   20th March
2018 CE 13th April   20th March
2285 CE 17th April   20th March
2355 CE 19th April One month drift here    21st March
3385 CE 2nd May   20th March

Notice there is one month drift by 2355 CE and it keeps increasing whence in 3385 CE the date is 2nd May, a total drift of 44 days.  This drift will keep continuingOur Sangrand will likewise keep drifting.

This will throw all the seasons out of normal making seasonal planning a problem.

As stated earlier this drift is due to precession (of the galactic circle).  When the stars are used as reference, precession manifests as a drift in the sidereal method.

The solution is to make a leap adjustment, which at present there is none.  For example the adjustment rule can be

When the sidereal sun goes to 0 (or any other suitable angle) degrees Pisces on 20th March, then make an adjustment to bring the date back to align with 0 degree Aries.  

On 20-Mar-2018 the sun will be about 6 degrees Pisces.   For 0 degree Pisces, the adjustment will be around 2400 CE.   This means dropping a month every approximately 2150 years.  Or we could drop a day every approximately 71 years which may be more practical and realistic.  Note that this is just throwing ideas.  A proper study has to be done to realise this.  Note this is the adjustment we mentioned in Part 4 in the table following Figure 22.

So at present the drift with the use of sidereal method is going to keep increasing.  Today the drift is about 24 days.

Note that CHET is signaled by PISCES presently in the Sidereal method.  CHET is the first month so it should start with ARIES.  Why does it start with PISCES?  We shall call this the CHET PARADOX and address this in the next article.


The next problem is that one system of event marking has movable dates when compared to another system of event marking.

The best example of this is the birthday of Guru Gobind Singh Ji.  This was recorded as POH Sudhi 7, 1723 Samvat (equivalent to 1666/7 CE)What does POH Sudhi 7 mean?  POH is the month, Sudhi is the 7th day after new moon.  Now the question is what does POH refer to? We take it that it is the SOLAR month.  Sudhi 7 is seven days after new moon.  So POH Sudhi 7 means the 7th day after new moon that falls in the month of POH.  Figure 40 illustrates the issue of movable birthdate of Guru Gobind Singh Ji.

Figure 40: Birthdate of Guru Gobind Singh 2019

40 Intercalary 20018

Guru Gobind Singh Ji’s birthdate was on 5-Jan-2017, then again on 25-Dec-2017.  The period between these dates is 12 lunar months.  In this year, 2018, there is an intercalary month.  This occurs in May-June, where JETH is extended to two lunar months.  See Figure 40.  Guru Gobind Singh Ji’s birthdate in 2019 will fall on 12th January.  The period from 25-Dec-2017 to 12-Jan-2018 is 12 MAN-MADE lunar months but 13 NATURAL lunar months. 

Why is this case?

This is because of the MAN-MADE intercalary month JETH in Jun-July which was added to JETH in May making one extended MAN-MADE month JETH which was actually two NATURAL lunar months.  The purpose for doing this is, as you know, adjustments to fit the lunar year into the solar year by the addition of intercalary month, so that long term drift would be avoided.

Is this correct from the birthdate perspective?  In one period Guru Ji’s YEAR between birthdates is 12 NATURAL lunar months and the next period it is 13 NATURAL lunar months.  It is sort of “out of normal”.  We would expect the birthdate to fall at regular intervals.

The proper way is to reference Guru Gobind Singh Ji’s birthday to a NATURAL reference.  The solar year the Sikh Panth is presently using the SIDEREAL SOLAR YEAR, which we pointed out above drifts, to mark Sangrand Additionally, lunar month phase (Sudhi 7) to pin the birthdate in a solar sidereal month further adds to the shift because the lunar year does not match the solar year.

Let us delve into Guru Ji’s birthdate to explore this in some depth.  

For this discussion we will use the tropical solar year which accurately (within limits or error of leap year adjustment) tracks the NATURAL planetary reference, the SUN.  The day we will use is midnight to midnight, which means the date changes at 12 midnight.

Lunisolar Bikrami system

Let us determine the position of the SUN on Guru Ji’s actual birthdate, POH Sudhi 7 1723 Samvat.  In 1723 Samvat POH massia was on 26-Dec-1666 at 12:00 midnight.  Therefore Sudhi 7 will fall 7 days after 26-Dec-1666 that is on 2-Jan-1667.  The position of the sun on POH Sudhi 7 1723 say at 12 noon is 12 degrees Capricorn.  

Note that in this analysis we have disregarded any errors due to the sidereal year drift.

Let us see what POH Sudhi 7 means in 1666, 2017, 2019 referencing to the position of the SUN.  This is reflected in the table below.

Date – Year Poh Sudhi 7
2-Jan-1667 12.00 degrees CAPRICORN
25-Dec-2017 3.63 degrees CAPRICORN
12-Jan-2019 21.73 degrees CAPRICORN

Notice there is a large variance in the planetary position for the birthdate of Guru Ji when determined using the sidereal solar month POH and lunar phase Sudhi 7.  It is possible that the error in birthdate could be about 1 lunar month.

Tropical solar year system

Based on accurate reference, NATURAL reference SUN, Guru Gobind Singh Ji’s birthdate should be on 12 degrees Capricorn EVERY YEAR based on the tropical calculation. This will occur on 2nd January every year. 

Based on this Guru Ji’s birthdate is 2-Jan-1667, 2-Jan-2018 and 2-Jan-2019.  Repeating the position of the SUN  for these dates gives the following results.

Date – Year 2-Jan at 6:00 AM 12 degree CAPRICORN
2-Dec-1667 12.00 degrees CAPRICORN At 6:00 AM
2-Jan-2018 11.78 degrees CAPRICORN At 11:00 AM
2-Jan-2019 11.53 degrees CAPRICORN AT 5:00 PM

In the table above, column 2 gives the angle for the date 2-Jan and time 6 AM and column 3 gives the time at angle 12 degrees Capricorn.

Notice that the angle difference is very small as compared to the lunisolar method above.  

The error in the angles is due to the fact that the year is 365 days but the actual value is 365.24219 days.  The maximum error as stated earlier can be about 1 day on the fourth year just before the leap adjustment.

Indian Sidereal solar year system

As a comparison consider the sidereal calculation.

Date – Year 2-Jan at 6:00 AM 12 degree CAPRICORN
2-Jan-1667 22.58 degrees SASGITTARIUS 21-Jan-1667 7:30 AM
2-Jan-2018 17.47 degrees SASGITTARIUS 26-Jan-2018, 8:30 AM
2-Jan-2019 17.20 degrees SASGITTARIUS 26-Jan:2019, 2:30 PM

In the table above, column 2 gives the angle for the date 2-Jan and time 6 AM and column 3 gives the time at angle 12 degrees Capricorn.

The drift in 2018 and 2019 is very large as compared to 2-Dec-1667 and 12 degree Capricorn Notice the difference in zodiac sign and angle (column 2 in table above) and the large difference (drift) in days (column 3 in table above), 19 days in 1667 and 24 days in 2018/2019.

Sidereal method is not realistically viable for event marking on earth mainly because of the drift.



There is a drift against NATURAL references in any event marking system.  It is a question of the drift amount (magnitude of error) when the leap adjustment is made. 

  • The error in the Gregorian system can be about 1 day. 
  • The error in the lunisolar system can be up to 1 lunar month
  • The error in the Sidereal system (e.g. used in Indian calendar) is not definable unless a leap adjustment is decided on.

The most appropriate method to convert an event from one calendrical system to another is to use the NATURAL reference viewed from the location of the event to make the conversion.  

NATURAL REFERENCE is used in the Gregorian calendar, which uses the SUN as a marker determined using the tropical method.  This is the most practical and accurate globally used method to mark events on earth.

The lunisolar Indian calendar uses the MOON and sidereal SUN to mark events. The Sikh Panth uses the sidereal solar method to fix Sangrand and lunar phase to fix the date. Unfortunately the sidereal method uses the STARS as reference and hence the position of the SUN or the MOON (or any other planet) will be incorrectly reflected when we are interested from the earths perspective especially for event marking.  The drift in the Indian sidereal solar calendar is what makes marking of events incorrect from the earth’s perspective.

CHET is the first month so it should start with ARIES but it is presently starting with PISCES.   Why?  This is a paradox (CHET PARADOX).  We will address this in the next part.

Rounding up we can say that the tropical method is most suitable to mark events on earth

As a minimum it would be prudent for the Sikh Panth to seriously consider using the tropical method to fix the Sangrand dates AS SOON AS PRACTICALLY POSSIBLE.

We will stop here for now.  

We have highlighted and explained the problems with the present system used in the Sikh Panth of marking events.  

In the next post, we will make a start at possible solutions to the calendar issue and then proceed to make a proposal at concept level for implementation as a “Sikh calendar”.

Thank you for reading.  Hope you enjoyed the discussion.  

Please do not hesitate to ask for clarification if you would like to understand further any of the concepts or information presented above.

ਵਾਹਿਗੁਰੂ ਜੀ ਕਾ ਖਾਲਸਾ ਵਾਹਿਗੁਰੂ ਜੀ ਕੀ ਫਤਹਿ

To be continued

00 Part 6 Main PIC