Ervad Marzban Hathiram at Frashogard.com writes a very informative piece on the Muktad Days at the end of the Parsi Calendar year.
Ten days before the Parsi New Year, fire temples around the city are dotted with roses and other flowers. One can see Parsi families dressed in spotless white, heads covered with scarves or caps, proceeding solemnly to their Agiaries with their hands full of floral offerings.
Parsis believe that during these ten days – called Farvardegan in Pahlavi or Muktad in Gujarati – the ruvans or souls of their dear departed visit the Earth. It is considered the duty of their living kin to welcome and honour them by the observance of various ceremonies. Each departed soul has his/her individual vase, which may be a simple copper one or an elaborately carved silver one. Families book tables at their respective Fire Temples, where these vases are kept, filled with fresh well water that is changed daily. For, it is in this water that the souls reside during their ten-day earthly sojourn.
Read the entire article at Frashogard.com