In Florida we call this an open plea. Basically just what you said. You can't come to an agreement with the prosecutor on a plea, so you're asking the judge to sentence you.
However, judges will also name court dates (at least in FL) after different legal proceedings, so it's possible that court date is just called Blind Plea Date. Or it's a day for all pleas, including negotiated ones, and the docket just shortens it and Blind is first alphabetically.