"ás" verus "as" when telling time

I can’t figure out why it’s different in both of these sentences. Why one “as” with the accent, and the other without? Any help would be appreciated! Thanks!

“O pôr-do-sol de amanhã é às 18h00.”
"É um quarto para as 8h00 da noite "

@davidkingcollage You have a combination of a preposition and a definite article in both cases, it’s just that there are two different prepositions. In the first case, the preposition contracts with the article and generates às, but in the second it doesn’t:

  • …é às 18h00 = é a (preposition) + as (definite article) 18h00 → This a + as = às (it’s a contraction)
  • …um quarto para as 8h00… → um quarto para (preposition) + as (definite article) 8h00… → no contraction applies here

More info on the preposition A and its contractions here: The Preposition A