noun
holiday; special day
Refers to a day that is special or different from ordinary days, often a holiday or festival day. Compare with 紋日 (also read ものび), which can have a similar meaning but is more specifically associated with special days in the pleasure quarters.
See also: 紋日
今日は物日だから、家族で出かけよう。
Today is a holiday, so let's go out as a family.
noun
day when prostitutes were obliged to take clients
Archaic term from the Edo period. On such days, prostitutes had to receive clients or pay a fee to avoid doing so. This sense is historical and not used in modern Japanese.
江戸時代の遊郭では、物日には遊女が客を取らなければならなかった。
In the pleasure quarters of the Edo period, on 'monobi' days, prostitutes had to take clients.