noun, used as a suffix, suffix
Suffix attached to nouns to indicate a date, a fixed or external attachment, or a date of effect. Common in administrative and business contexts.
この書類は2024年4月1日付けで有効になります。
This document becomes effective as of April 1, 2024.
契約書に日付を記入してください。
Please fill in the date on the contract.
外付けハードディスクを購入した。
I bought an external hard disk.
付く is an intransitive verb meaning 'to be attached', while 付け is a suffix derived from the transitive verb 付ける.
Derived from the verb 付ける (つける, 'to attach'), used as a suffix to indicate attachment, dating, or external addition.