Question

The 24-hour clock is uncommon in Spanish-speaking countries

Answer 1

HI asrin, not really.... we use the 12 hour clock, we say

las 12 de la noche las 12 del mediodía

 I think its just the same as most English countries- where we use both 12 hour and 24 hour clocks! Though that is an interesting question because i'v only learnt to tell the time on a 12-hour clock!