jyotish shastra men rituon tatha kal, paksh, uttarayan tatha dakshinayan, uttar gol aur dakshin gol ka atyadhik mahatva hai. uttar gol men devta prithvi lok men vicharan karte hain, vahin dakshin gol bhadra mas ki purnima ko chandralok ke sath-sath prithvi ke najdik se gujrta hai. isi mas ki pratiksha hamare purvaj pure varsh bhar karte hain. ve chandralok ke madhyam se dakshin disha se apni mrityu tithi par apne ghar ke darvaje par pahunch jate hain aur vahan apna asamman ya apni nai pirhi men nastikta ko dekh dukhi hokar shrap dekar chale jate hain. ve pitrilok men jakar apne sathiyon ke samaksh apne parivar ka dukh prakat karte hain aur pure varsh dukhi rahte hain.
agar unki nai pirhi pitron ke prati samman rakh rahi hai to ve dusre pitron se milakar apni pirhi ki barai karte hue fule nahin samate hain. aisa varnan shraddh mimansa men aya hai. jyotish shastra ke anusar bhi jab surya narayan kanya rashi men vicharan karte hain tab pitrilok prithvi lok ke sabse adhik najdik ata hai. shraddh ka arth purvajon ke prati shraddha bhav se hain. jo manushya unke prati unki tithi par apni samathrya ke anusar falful, ann, mishtann adi us par prasann hokar pitri use ashirvad dekar jate hain.
pitron ke lie kie jane vale shraddh do tithiyon par kie jate hain, pratham mrityu ya kshay tithi par aur dvitiya pitri paksh men. jis mas aur tithi ko pitar ki mrityu hui hai athva jis tithi ko uska dah sanskar hua hai, varsh men us tithi ko ekodisht shraddh kiya jata hai. ekodisht shraddh men keval ek pitar ki santushti ke lie shraddh kiya jata hai. ismen ek pind ka dan aur ek brahman ko bhojan karaya jata hai.
pitripaksh men jis tithi ko (ashvin mas ke krishnapaksh men) pitar ki mrityu tithi ati hai, us din parvan shraddh kiya jata hai. parvan shraddh men 9 brahmanon ko bhojan karane ka vidhan hai, kintu shastra kisi ek hi satvik evan sandhyavandan karne vale brahman ko bhojan karane ki bhi agya dete hain. brahm puran men varnan aya hai ki jo log shraddh nahin karte, unke pitri unke darvaje se vapas dukhi hokar chale jate hain pure varsh shrap dete tatha apne sage sanbandhiyon ka rakt chuste rahte hain aur varsh bhar unke ghar men manglik karya nahin hote. bhartiya jyotish shastra men pitri dosh ka sabse adhik mahatva hai. yadi ghar men koi manglik karya nahin ho rahe hain, roj nai-nai aften a rahi hain, admi din-hin hokar bhatak raha hai, ya santan nahin ho rahi hai, ya viklang paida ho rahi hai to iska mukhya karan yah hai ki us vyakti ki kundli men pitri dosh hai, aur yadi vah vyakti shraddha bhav se apne purvajon ke prati shraddh paksh ki amavasya ko vidhi vidhan ke sath pind shraddh karta hai, to pitri usse prasann ho jate hain tatha use ashirvad dekar jate hain.
shraddh mimansa men varnan hai ki agar vyakti ke pas vastav men shraddh karne ke lie kuch dhan nahin hai, to vah donon hathon se kusha uthakar akash ki or kar dakshinmukhi hokar apne purvajon ka dhyan kar rone lage, aur jor-jor se kahe ki he mere pitro ! mere pas koi dhan nahin hai. main tumhen in ansuon ke atirikt kuch nahin de sakta to uske pitri uske ansuon se hi tript hokar chale jate hain. karn ke ardhamrityu ke bad prithvi par ane ki katha prasiddh hai. unke is agaman ko karnagat aur apabhransh men kanagat kaha gaya hai. katha hai ki ek bar karn ghayal avastha men ardhamrityu ko prapt hue.
svarg men jakar unhen bhukh-pyas ka anubhav hua, to unhonne pani aur bhojan manga. tab dharmaraj ne unhen sona (svarna) khane evan pine ke lie diya aur kaha ki tumne jivan bhar svarn hi dan kiya hai, islie svarn ka upbhog karo. tab karn ne ashvin krishn paksh ke keval 15 din mange, jismen unhonne prithvi par akar anna-jal ka dan kiya. is paksh men pitron se sanbandhit dan keval brahmanon ko diya jana chahie. kisi anya sanstha ya anathalay ko sahanubhuti rashi to di ja sakti hai, kintu bhojan par brahman ka hi adhikar hai, kyonki vah brahm ka sidha pratinidhi hai.
yadi kisi ko apne purvajon ki mrityu ki tithiyan yad nahin hon, to vah amavasya ke din apne gyat-agyat purvajon ka vidhi vidhan se pinddan, tarpan, shraddh kar sakta hai. iska 15 din ka punya fal milta hai.