The Croatian for 'What time is it now?' is Koliko je sada sati? or Koliko je sati? for 'what time is it?'
Once you know the numbers, there are various ways of forming the time (on the hour). One is by putting Sada je ... before the time. In Croatian je (the short form of to be), can not start a sentence.
Use the number, followed by i 'and', followed by sat 'hour'.
Sat 'hour' changes its case depending on the number which follows. It uses the genitive singular (when followed by two, three or four) and genitive plural (when followed by other numbers greater than one). This also happens when using numbers for purposes other than telling the time.
So sat becomes sata in the genitive singular and sati in the genitive plural. E.g. three hundred hours is tristo sati.
Svaki dan radi 8 sati 'Every day I work eight hours'.
The words i pol is used meaning 'and a half'. E.g. devet i pol sati 'ten thirty'.
The preposition do 'to, until' is used.
Radim do 17 sati. 'I work until five'.
The Croatian preposition u is used.
U sedam sati 'at seven o'clock'.