According to the America250 law, the national time capsule should be unearthed in 2276.
The United States Semiquincentennial Commission Act of 2016 specified that the capsule be buried on July 4, 2026, and opened on the occasion of the United States’ 500th anniversary on July 4, 2276. That creates a 250-year interval between burial and planned opening.
The design looks beyond the immediate celebration by asking future Americans to examine artifacts from the country’s 250th year. In that sense, the capsule is both an anniversary project and a long-term historical record.
The year 2276 is not the 300th anniversary; it is the 500th anniversary of the Declaration-era founding date. The next major anniversary after 2026 is the Tricentennial in 2076, exactly 50 years later.