вставьте in, on, либо at

At ten o'clock, at 2.15
On Monday, on Tuesday
On Monday morning, on Tuesday morning
On Christmas, on Easter
On January, on February
On 1st May, on 7th June
In 1930, in 1992, in 2001
In the summer, in the winter

*Поставь спасибо, если посодействовала) Для тебя не трудно, мне приятно