noun
unlucky day; bad day
Refers to a day when things go wrong or misfortune is expected, often in a superstitious or colloquial sense.
今日は厄日だ。朝から何もかもうまくいかない。
Today is an unlucky day. Nothing has gone right since this morning.
厄日には大事な決断を避ける人もいる。
Some people avoid making important decisions on unlucky days.
noun
critical day (for crops)
Agricultural term for a day when weather or other conditions are especially critical for crop growth or harvest.
農家にとって霜が降りる日は作物の厄日だ。
For farmers, a day with frost is a critical day for the crops.