The Aashirwad (Blessings) ceremony is performed before the wedding. The paatro/paatri are to be blessed by the elders of the both the families. The paatro/paatri do not accompany the family on these occasions(in most cases). This is similar to an engagement.
The ceremony is arranged at both the sides i.e. paatro or paatri. The dates for the aashirwaad are decided using panjika or panchanga ( Panchangam means five attributes of Hindu calendar day that is Tithi, Vaar, Nakshatra, Yoga, and Karana). Typically the aashirwaad are organized couple of days before the marriage marks the beginning of the festivities.