also: ワンデイ
noun which may take the genitive case particle 'no', noun
one-day
Describes something lasting or valid for a single day, such as a ticket, pass, or event.
１Ｄａｙパスを買って、一日中バスに乗り放題だった。
I bought a one-day pass and could ride the bus all day.
noun which may take the genitive case particle 'no', noun
single-use; daily-disposable
Commonly used for contact lenses and similar products that are used once and discarded.
最近、１Ｄａｙのコンタクトレンズに変えた。
I recently switched to daily-disposable contact lenses.
日帰り is a native Japanese term for a day trip or returning on the same day, while １Ｄａｙ is a loanword used for products or services valid for one day.
使い捨て means 'disposable' in a general sense, while １Ｄａｙ specifically implies a one-day or single-use cycle, often for contact lenses.
Loanword from English 'one day', adapted into Japanese with the numeral １ and the English word 'Day' or katakana デー/デイ.