noun
purchase date; date of purchase
Refers to the date on which something was bought. Common in receipts, warranties, and record-keeping.
領収書に購入日が記載されています。
The purchase date is written on the receipt.
保証書には購入日を記入してください。
Please fill in the date of purchase on the warranty card.
発売日 is the release date or date when a product becomes available for sale, not necessarily when a specific item was bought.
Compound of 購入 (purchase) and 日 (day/date).