noun
auspicious day for any activity
In the traditional Japanese calendar, a day when all activities are considered fortunate; often chosen for weddings, groundbreaking ceremonies, and other important events.
天赦日は何をしても良い日とされています。
Tenshanichi is said to be a day when anything you do will go well.
結婚式は天赦日に合わせて決めました。
We set the wedding date to coincide with Tenshanichi.
一粒万倍日 is another auspicious day for starting new ventures, but it is based on a different calculation. It is often combined with 天赦日 for maximum luck.
From 天 (heaven) + 赦 (pardon, forgive) + 日 (day), literally 'day of heavenly pardon'. The name reflects the belief that on this day, heavenly deities forgive all transgressions and bless all endeavors.