в десять часов

at ten o'clock

→ в
phrase Rare #49,011
at ten o'clock Used to state that something happens at 10:00. The context may specify morning or evening; в десять часов вечера means “at ten o'clock in the evening.”
RU: Я обычно ложусь спать в десять часов.
EN: I usually go to bed at ten o'clock.