Using org-agenda-time-grid with lists

[steve-humphreys]

I am trying to insert finer timings in org-agenda with the following code.
Haw can one pass a list in a list?

(setq tm '(number-sequence 800 2000 30))
(setq org-agenda-time-grid '((daily today require-timed)
   tm "......" "----------------"))


But this works well

(setq org-agenda-time-grid '((daily today require-timed)
   (800 900 1000 1100 1200 1300 1400 1500 1600 1700  1800 2000)
   "......" "----------------"))