Complete
00:00:00
8 10 13 16 6 5 19 1 17 2 9 14 3 11 15 4 12 18 7
  1. 5a Person who creates or improves e.g. software (9)
  2. 8a Stage (4)
  3. 9a Bald (8)
  4. 10a One using a rod and a line (6)
  5. 11a Neckwear (6)
  6. 13a Edinburgh performance-arts festival (6)
  7. 15a Mollusc with a ribbed shell (6)
  8. 16a Arm of the North Atlantic Ocean (5,3)
  9. 18a Protruding tooth (4)
  10. 19a Well-bred fellow (9)
  11. 1d Airship (8)
  12. 2d Breeze (6)
  13. 3d Astrological system (6)
  14. 4d Eagerness (4)
  15. 6d Plan for a journey (9)
  16. 7d Set up (9)
  17. 12d Former maximum-security federal prison (8)
  18. 14d Artificial (6)
  19. 15d President of Venezuela 1999-2013 (6)
  20. 17d Egyptian port (4)