Pradosham, and how the day is chosen

Pradosham is the three muhurtas following sunset. The observance date is selected by applying the trayodashi rule to that period.

Pradosham falls twice a lunar month. The dates are listed for 2026 and 2027; below is how each day is chosen.

First, what the window is

The day is divided into five parts (pratah, sangava, madhyahna, aparahna and sayahna), and pradosha sits outside that division: the three muhurtas after sunset. A muhurta is 48 minutes, so the window runs roughly two hours and twenty-four minutes from sunset.

Pradosham uses the period after sunset. A daily list of tithis at sunrise may therefore show a different date from the observance list.

Then, which trayodashi takes it

The rule considers trayodashi during the period after sunset. When two consecutive days are possible, it gives these conditions:

• Covered on both days, or touching the window equally: the later day.
• Touching unequally: the day with more of it, even if that is the earlier day, provided the excess is enough for the puja and the meal.
• If that excess is not enough: the later day.
• Covered on neither: the later day.

In short: the later day, unless the earlier day has clearly more of the window, enough for the puja and the meal.

The dates this gives

Applied to September and October 2026, the rule gives 8 and 24 September, then 8 and 23 October.