Historical clue formulations

• *Terrific messenger at Hogwarts? — 2023-01-29
• "He's prepared a ___ of popcorn for himself ..." — 2010-02-07
• Feb. 7, 2010, the date of this event's number 55-Across — 2009-06-10
• Where this puzzle's theme pairs would like to meet — 2007-11-20
• January event, or a great bird — 2001-10-17