Time prepositions (on/in/at)

[magdala]

English Language Tests, Intermediate level

ESL/EFL Test #206 "Prepositions of Time and Date (4)", question 6

......... Independence Day, we always go to the fair and watch the fireworks at 11 pm.

(a) About
(b) On
(c) (none)

English Language Tests, Intermediate level

ESL/EFL Test #206 "Prepositions of Time and Date (4)", answer 6

On Independence Day, we always go to the fair and watch the fireworks at 11 pm.

Correct answer: (b) On

Your answer was: incorrect
Independence Day, we always go to the fair and watch the fireworks at 11 pm.
_________________________

Why "on" is not applicable?

[Pamela]

On is applcable here. Special dates and festivals are used with preposition on.