[Advaita-l] shivaraatri dates this year

[Anand Hudli]

Shri Raghav Kumarji,
>>>>
One small follow up question - why does the tithi ending time differ in the
two methods. My first level understanding about tithi determination is that
it's the time taken by the moon to move 12 degrees away from the sun. And
so 30 tithis will be there in one month. The tithi durations will differ
because the lunar orbit is not in the ecliptic plane but inclined at about
5 degrees to the ecliptic.
>>>>

There are different methods of computing the moon's and sun's position
(specifically celestial longitude). The sUryasiddhAnta is an ancient method
but modern methods promise a higher degree of accuracy. This has led many
panchanga makers to opt for modern methods
or more recent methods such the dRg-gaNita method. The difference in the
moon's position, especially, depending on the method used, could run into
degrees of the arc, not just seconds or minutes. This could lead to the
difference in tithi ending times of several hours that we see
in different panchangas. This in turn could lead to the same observance,
eg. shivarAtri, being declared on different dates by different panchangas.

>>>>
So some tithis will be long like about 29 hours
and some short like 19 hours or so in each lunar month. In the geocentric
astrological chart this can be visualized as the moon moving sometimes
faster (shorter tithi) and sometimes slower (longer tithi)That is also why
lunar eclipses will not occur every month. Also right now a lunar eclipse
has just occurred so the moon is on the ecliptic plane . Which means the
tithi duration will be relatively shortest now and longest 15 days later .
>>>>

The variation in the moon's speed directly follows from Kepler's law for
bodies in elliptical orbits, which states that the line joining an orbiting
body (moon) with its center (at one of the foci) sweeps out equal areas in
equal intervals of time. The speed at the perigee when
the moon is closest to earth is higher than the speed at the apogee when
the moon is farthest from earth. A nice explanation is found here:
http://www.phy6.org/stargaze/Skepl2A.htm
The speed of the moon may not have anything to do with eclipses per se. If
the moon happens to be near the perigee at the time of eclipse, then the
speed would also be higher. Else not. Yes, you are right in saying a faster
(slower) moving moon means shorter (longer) tithis.

Anand




On Thu, Feb 1, 2018 at 10:26 PM, Anand Hudli <anandhudli at hotmail.com> wrote:

> Correction:
>
> "The nishItha kAla is obtained by dividing the duration of the night
> (i.e. from sunset to sunset the next day) into 15 parts and taking the
> eighth such part."
> should read- "The nishItha kAla is obtained by dividing the duration of
> the night (i.e. from sunset to *sunrise* the next day) into 15 parts and
> taking the eighth such part."
>
> Anand
>
>
> On Thu, Feb 1, 2018 at 10:18 PM, Anand Hudli <anandhudli at hotmail.com>
> wrote:
>
>> >The kanchi mutt is following the कालमाधवीयं and sriCngeri mutt is
>> following धर्मसिन्धु...
>>
>> >Former is celebrating on 14th and the later on 13th !!
>>
>> Dear Shri Sriramji,
>>
>> I looked at both the (Kannada) Sringeri and (Telugu version) Kanchi Matha
>> Panchangas. First of all, the tithi ending times are telling us that
>> Sringeri uses (the ancient) Surya Siddhanta method of determining tithi
>> ending times, while Kanchi uses dRg-gaNita. The starting and ending time
>> for Chaturdashi tithi are 1) 10:15 PM on Feb 13 and 12:11 AM on Feb 15 as
>> per Surya siddhAnta and 2) 10:34 PM on Feb 13 and 12:46 AM on Feb 15 as per
>> dRg-gaNita. Now, the rule for mahAshivarAtri states that Chaturdashi should
>> prevail during the nishItha kAla of the day when we observe it. The
>> nishItha kAla is obtained by dividing the duration of the night (i.e. from
>> sunset to sunset the next day) into 15 parts and taking the eighth such
>> part. The sunset times at Sringeri and Kanchi differ too, since Sringeri
>> sunset is at 6:33 PM and Kanchi sunset is at 6:16 PM. Taking the duration
>> of the night as approximately 12 hours (this is sufficient for this
>> instance, although the actual duration of night is slightly more than 12
>> hours), each 1/15 part of the night is 48 minutes, which is, by the way,
>> the duration of a muhUrta. The eighth such part (nishItha kAla) starts 5
>> hours 36 minutes after sunset. In Sringeri, this would be 12:09 AM on Feb
>> 14 and in Kanchi it would be 11:52 PM on Feb 13. On the next day, the start
>> of nishItha kAla is about the same in the two places. The ending time for
>> the nishItha kAla would be 12:57 AM on Feb 14 in Sringeri and 12:40 AM on
>> Feb 14 in Kanchi. The interesting point to note is that the vyApti of
>> Chaturdashi is kArtsnyena (complete, as dharmasindhu puts it) in Sringeri
>> on Feb 13-14 night and ekadeshena (partially) on Feb 14-15 night as per
>> Sringeri's method, ie. sUrya siddhAnta. When this happens, the rule for
>> shivarAtri states that the first night, i.e. Feb 13-14, should be selected
>> for observing shivarAtri (paredyuH nishItha-ekadesha-vyAptau pUrvedyuH
>> saMpUrNatadvyAptau pUrvaiva). Hence Feb 13-14 is the shivarAtri date for
>> Sringeri. The same would have been the case for Kanchi, had it not been for
>> the dRg-gaNita method which makes the ending time of Chaturdashi 12:46 AM,
>> beyond the ending of nishItha kAla at 12:40 AM. As an interesting twist,
>> there is not ekadesha-vyApti but saMpUrNa-vyApti even on the second night,
>> i.e. Feb 14-15 *and* saMpUrNa-vyApti on the first night , i.e. Feb 13-14 in
>> Kanchi! When this happens, another rule applies which says the majority of
>> the dharmashAstra-kAras recommend the second night, i.e. Feb 14-15 in this
>> case, while Hemadri and those who follow Hemadri recommend the first night.
>> It appears that Kanchi has taken the majority opinion, which includes
>> weighty granthas such as nirNyaya-sindhu, kAlamAdhava, and puruShArtha
>> chintamaNi. Hence, Feb 14-15 is the shivarAtri date for Kanchi.
>>
>> Anand
>>
>>
>