"The temperatures fell last night."
Translation:Temperaturile au scăzut azi-noapte.
Both do indeed mean "last night". I am not sure why that is, but since most nights extend on two different days (except at the poles), one may argue that you can call last night both ieri-noapte and azi-noapte.
However, azi-noapte is more common than ieri-noapte, so you can just stick with the former or you can say noaptea trecută (literally "last night").
you are correct BUT in english ( or in french etc. LAST night does not mean YESTERDAY night. DUO is always asking us to translate word-for word ( literally) why not here ? I perfectly understood that we should give both answers as correct but I did not do it. on purpose.I wanted to see DUO's reaction. Now i have seen it !
"azi-noapte" este o exprimare populara... subintelegandu-se ca este vorba de ultima noapte , inclusiv din primele ore ale zilei.... cand cu adevarat temperaturile sunt cele mai scazute... In romaneste se foloseste ..Temperaturile au scazut in primele ore ale diminetii...
England has difficulty referring to the daylight hours of the 24th December. 'Christmas Eve day'! I presume that's why some stories begin ' 'twas the night before Christmas', meaning specifically Christmas Eve evening, leading into Christmas Day!!