Pradosh Vrat

(“twilight vow”) Religious observance
celebrated on the thirteenth day of each
lunar fortnight, mainly by women, often
for the birth of children or to sustain the
general family welfare. The vow (vrat) is
dedicated to the god Shiva, and its most
important part takes place on the
evening of the thirteenth day (the word
pradosh is interpreted as meaning “twilight”) when worshipers present Shiva
with the sixteen traditional offerings
(upacharas), following which they may
take their only meal of the day. In
some cases worshipers stay awake
through the night so that the observance
may finish on the fourteenth day of
the month, a lunar day connected
with Shiva. When the thirteenth day
falls on a Monday (associated with
Shiva), Saturday (associated with
Saturn), or Sunday (associated with
the Sun), this rite is believed to be
especially efficacious.