It looks like you’re asking about the release date for Oops… I Did It Again. Here’s the concise answer:

• The single “Oops!... I Did It Again” was released on April 11, 2000 in the United States (radio) and May 1–May 3, 2000 in other markets, with the single widely released in May 2000. The album Oops!... I Did It Again followed later, being released on May 3, 2000 in several regions and May 16, 2000 in others.

If you want, I can tailor this to a specific region or format (e.g., UK cassette single release date, US radio date, etc.).