The expression noon and a half (12:30) is commonly said, however, it is incorrect. For the middle fractional numeral must agree in gender with the word of which it is a fraction.
Look at the examples:
I bought three and a half meters of fabric (three meters plus half a meter).
I walked two leagues and a half to get here. (two leagues plus half a league).
We can conclude that the correct expression is half past noon, since the fractional numeral agrees in gender with the word hour, although this is implied.
My glasses or my glasses?
The word glasses, as well as congratulations, vacation, nuptials, is commonly used in the plural, since its singular, “glass”, is unknown to most.
As for its use, there are two options: either we use everything in the plural – my new glasses; or we use everything in the singular – my new eyeglass.
The structure presented in the plural is preferred.
By Marina Cabral
Specialist in Portuguese Language and Literature
Source: Brazil School - https://brasilescola.uol.com.br/gramatica/meiodia-meio-ou-meiodia-meia.htm