Gajachchhaya Yoga is formed by combination of Sun, Moon and 2 tithis (Lunar Days) which are Trayodasi and Amavasya.
This yoga is formed when sun transits through Hasta Nakshatra in Virgo (Kanya Rasi) once in a year and mostly during Pitru Paksha.
In 2019, Gajachchhaya Yoga occurs only once on Amavasya (New Moon Day), which is 28 September.
In Asia, Australia (except New Zealand) this yoga occurs after sunset and before sunrise, which makes it non applicable.
People in Europe, North and South American countries can utilise this yoga and offer prayers to their ancestors.
The combination when the Sun is in Hasta Nakshatra and the Moon is in Magha Nakshatra during Trayodasi Tithi of Pitru Paksha is known as Gajachchhaya Yoga, but this combination does not occur in 2019.
Next occurance of Gajachchhaya Yoga is when the Sun and Moon are in Hasta Nakshatra during Amavasya Tithi of Pitru Paksha is also known as Gajachchhaya Yoga.
So, there might be one or two Gajachchhaya Yoga during Pitru Paksha. This auspicious combination occurs either on Trayodashi Tithi or on Amavasya Tithi.
Gajachchhaya Yoga (गजच्छाया योग) does not form every year. But whenever Gajachchhaya Yoga occurs during Pitru Paksha, it is considered highly auspicious for performing Shraddha rituals and charity.
Transit of Sun in Hasta nakshatra happens every year during September-October. But this should be Bhadrapada Maasa (where fullmoon forms in Uttara Bhadrapada Nakshatra) and not adhika maasa.
Second half of this month (when Moon is waning between fullmoon to next newmoon) is called Mahalaya Paksha or Pitru Paksha and no auspiscious event is performed during these 15 days.
Traditional astrologers do not check any horoscopes and postpone all astrological advises.
These are the days to offer Shraddh to deceased ancestors in a family.
Pitru Dosha Causes, Effects & Remedies.
Curses of forefathers is said to cause pitra dosham according to puranas, but reality is that, one faces this only because of his/her past life deeds.
There are be millions of souls in this world who are not resting in peace. All the souls are ancestors of someone who are alive today.
But, reality is that Pitra devatas are not the one who are deceased, but the ones who are never born and will never die.
They reside in the form of DNA and continue that ‘Gotra‘ through ‘Y’ chromosome of males in that family.
When one person suffers from pitru dosha, his/her family will struggle to see next generation smoothly.
Either they will not have kids, or their children will seperate from them, or no male kids in next generation will end their Gotra.
For Pacific Time Zone (West Coast of USA and Canada GMT -7) :
Amavasya Gajachchhaya Yoga Starts on 28th September 2019 from 09:33 hrs PDT and ends at 11:26 hrs PDT
For Central Time Zone (USA and Canada GMT -5) :
Amavasya Gajachchhaya Yoga Starts on 28th September 2019 from 11:33 hrs PDT and ends at 13:26 hrs CDT
For Eastern Time Zone (East Coast of USA and Canada GMT -4) :
Amavasya Gajachchhaya Yoga Starts on 28th September 2019 from 12:33 hrs PDT and ends at 14:26 hrs EDT
For South America (GMT -3) :
Amavasya Gajachchhaya Yoga Starts on 28th September 2019 from 13:33 hrs PDT and ends at 15:26 hrs
For United Kingdom (GMT+1) :
Amavasya Gajachchhaya Yoga Starts on 28th September 2019 from 17:33 hrs PDT and ends at 19:26 hrs
For countries in GMT+2 time zone :
Amavasya Gajachchhaya Yoga Starts on 28th September 2019 from 18:33 hrs PDT and ends at 20:26 hrs
But as Sun set occurs around 20:00 hours, they have lesser time to finish the ritual.
In Africa and Asia, Gajachchaya yoga starts after sunset, so rituals cannot be done.
In Australia, it ends before sunrise.
Duration of Gajachchhaya Yoga on Amavasya is 1 Hour 53 Minutes.
For New Zealand (GMT+11) :
Amavasya Gajachchhaya Yoga Starts on 28th September 2019 from 05:33 hrs PDT and ends at 07:26 hrs.
They can do the amavasya ritual after sun rises around 06:30 am.
Gajachchhaya Yoga is useful when it falls during day time and it has no value when it falls during night time.
So, in 2019 Pitru Tarpan or Shraddh should be performed by people whose father passed away during that time and date.