UPLATE
| Date | Clue |
|---|---|
| 2025-05-15 | Burning the midnight oil, say |
| 2024-10-15 | Still awake after midnight, say |
| 2020-03-28 | Watching TV after midnight, say |
| 2014-03-12 | Pulling an all-nighter, e.g. |
| 2014-01-02 | Burning the midnight oil |
| 2009-07-18 | Watching Letterman or Conan, say |
| 2007-06-30 | Burning the midnight oil |
| 2005-10-03 | Still awake at 1 a.m., say |
| 2003-12-07 | Burning the midnight oil |
| 2001-05-10 | Burning the midnight oil |
| 1999-07-11 | Burning the midnight oil, so to speak |
| 1996-10-05 | Working through the night |