The eleventh day (ekadashi) of the bright (waxing) half of
the lunar month of Shravan (July–August) and the eleventh day of the brilliant
(waxing) half of the lunar month of Paush (December–January) are religious
observances that occur twice a year.
These are devoted to the deity Vishnu, as are all
eleventh-day observances.
Most Hindu holidays have mandated ceremonies, which
generally include fasting (upavasa) and devotion, and frequently promise
particular rewards if they are followed faithfully.
Following the ekadashi ceremonies on these days is said to
result in the birth of a son (putra), which is a key worry in Indian culture.
Sons are required in this world and the next, not just to
care for their aging parents, but also to carry out specific ancestral
ceremonies after death.
The fact that this specific ekadashi happens twice
throughout the year—the only ekadashi to do so—evidences the power of this
longing for sons.
You may also want to read more about Hinduism here.
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