Ordinal numbers in dates and clock time

You can already count: jedan, dva, tri, četiri, pet. Those words answer how many. But to answer which one in a row — the first floor, the second street, the third coffee of the day — Serbian uses a second set of number words. The good news is that you already know how they behave: they are ordinary adjectives, with the same -i / -a / -o endings you have been putting on dobri, dobra, dobro.

The ordinal numbers

The ending is chosen by the noun, exactly as with any adjective: prvi sprat (masculine), prva stanica (feminine), prvo pitanje (neuter).

And because they are adjectives, they take case endings too, wherever the sentence puts them. After na and u meaning 'at', that is the locative you already know:

• na prvom spratu — on the first floor
• na petom spratu — on the fifth floor
• na drugom mestu — in the second place
• u drugoj ulici — on the second street
• u trećoj kući — in the third house

In a compound number, only the last word becomes an ordinal. Everything before it stays as it is: dvadeset prvi (21st), trideset prvi (31st), dvadeset peta (25th, feminine).

drugi means both second and other. Drugi dan is either 'the second day' or 'another day' — the situation tells you which.

The days of the week

To ask which day it is: Koji je danas dan? — Danas je četvrtak. To say on a day, use u plus the accusative, which is why the feminine days change their ending: u sredu, u subotu, u nedelju.

nedelja is both Sunday and week. Ova nedelja is 'this week'; u nedelju is 'on Sunday'.

The date

The day of the month is an ordinal, always masculine, because the word standing behind it is dan. The month keeps its plain form after it.

• Koji je danas datum? — What is the date today?
• Danas je peti oktobar. — Today is the fifth of October.
• Danas je dvadeset prvi mart. — Today is the twenty-first of March.
• Moj rođendan je osmi jun. — My birthday is the eighth of June.

• januar, februar, mart, april, maj, jun
• jul, avgust, septembar, oktobar, novembar, decembar

The clock

Here comes the surprise: the clock does not use ordinals. The hour is an ordinary number, and sat behaves exactly as the numeral rule you already know says it should — jedan sat, dva sata, pet sati.

To ask the time: Koliko je sati? — Sada je devet sati. To arrange a meeting, put u in front of the hour: Vidimo se u osam sati. — 'See you at eight.' Voz kreće u šest i deset. — 'The train leaves at six ten.'

The trap is mixing the two systems. A date takes an ordinal — peti oktobar, the fifth of October. An hour takes a plain number — pet sati, five o'clock. Peti sat would mean 'the fifth lesson period', not five o'clock.