Dear sir
Poorvangam for Upanayanam can be performed the day before upanayanam. If any of thithi or natchatra or tyoga is not favaourable then it can be dolne
one day before. The ahathu vathiyar can guide you in this regard.
Further I wish to inform you that poorvangam includes the following samskaaranga. Jatha karma,.Uthaana, Naamakaranana, Annapraasana,Prabaasagamana,
Pidavarthana chowlam. for each of these samskarams as per dharmasastra the kalam had dertermined. But we are not dling the samsarams oat the prescriebed time.
So totaly al these samskarams are done with a small prayachitham on oneday i.e poorvangam In poorvangam Nandhi is inculded but udaga santhi is seperate
to purify the vadu or thambathikal.
In my opinion already we are doing the samsklarams belated. So this should be done before upanayanam then onely the boy is eligible to do upanayanam.
Nohin wrong in doing poorvangam previously. If it is poossible udakasanthi can be done the day before upanayanam Kindly consult your ahathuvaathiyar or
brahaspathi who is doing upanayanam. I f poossibel also informme the views of vatthiyar so it is helpuf for others.
Rajappa Namakkal