The time in Spanish is fairly similar to English but with a few slight differences that may lead you astray.
To ask what time it is, say:
“¿Qué hora es?” (What time is it?)
To answer, say:
“Son las ______” (It’s ______o’clock) — for example, “Son las cinco” (It’s five o’clock)
Note that when it’s one o’clock (1:00 p.m. or 1:00 a.m.), we use es instead of son, because una is singular. So, you would say:
“Es la una.” (It’s one o’clock)
Unlike the date, the time is always feminine, so it’s “es la una“ or “son las dos,” never “es el uno” or “son los dos.”
As you know the numbers 1-12, you can already say the time when it’s on the hour without a problem:
It’s 2 p.m. = Son las dos
It’s 4 p.m. = Son las cuatro
Note that if you want to distinguish between whether it’s a.m. or p.m., you can add de la tarde (p.m., afternoon) or de la noche (p.m., nighttime)—for example, “son las dos de la tarde” (it’s two in the afternoon)—or de la mañana (a.m.)— for example, “son las dos de la mañana” (it’s two in the morning).

You might also need:
Midday — Mediodia
Midnight — Medianoche
Quarter past _____ — _____ y cuarto
Half past _____ — _____ y media
Quarter to _____ — _____ menos cuarto
Here are a few examples to get you started working with all these numbers:
It’s 5:15 (quarter past 5) — son las cinco y cuarto
It’s 5:30 (half past 5) — son las cinco y media
It’s 5:45 (quarter of six) — son las seis menos cuarto
Notice that to say 5:45, you can use cinco con cuarenta y cinco or you have to count backwards from 6 o’clock to say seis menos cuarto (quarter of six).
To talk about times that aren’t made up of quarters or halves, you just use the numbers we already know.
5:05 — cinco y cinco
5:20 — cinco y veinte
5:40 — seis menos veinte
5:50 — seis menos diez
Also note that many Spanish-speaking countries use the 24 hour clock, so they’re more likely to say “son las catorce” (it’s 14:00) than they are to say “son las dos de la tarde.” This can also differ between individuals within each country, just as it does in many English-speaking countries.
Good practice for telling the time can be found on websites like this one and this one.
