| Answer | Crossword Clue |
|---|---|
| NIGHTOWL | Keeper of late hours. |
| OWL | Keeper of late hours, informally |
| OWLS | Keepers of late hours. |
| vesper | the sixth of the seven canonical hours or the Christian service for it in the late afternoon or evening; evensong |
| HEARTANDSOUL | Late hours |
| STAYUP | Keep late hours |
| NITE | Late hours, informally |
| SATUP | Kept late hours. |
| SITUP | Keep late hours. |
| WEE | Late-hours word |
| SATUP | Kept late hours |
| NITE | Late hours, commercially |
| TAPS | Late-hours tune |
| NITE | Late hours, in ads |
| NIGHTMARES | What horses keep late hours? |
| AEIOU | Quintet seen in late-night hours? |
| AEIOU | Group seen in late-night hours? |
