This section summarizes some of the time expressions presented elsewhere in this Grammar.
The preposition (if any) and the case form you use to state the time when something occurs depends on the noun: saying that something happened on a certain day is different from saying that it happened in a certain month or season.
в + Accusative
minutes в двђдцать (Acc.) минџт вторћго at twenty minutes past one
hours в чђс (Acc.) at one o'clock
  в двђ (Acc.) часђ (Gen.) at two o'clock
day names в срљду on Wednesday
'day' в дљнь (Acc.) рождљния (Gen.) on (one's) birthday ( Lit. 'day of birth')
в + Prepositional/Locative
month names в январљ in January
'month' в ітом мљсяце (in) this month
'year' в прћшлом годџ (Locative) last year
Instrumental (without preposition)
times of the day and year
  џтром/днём/вљчером/нћчью in the morning/afternoon/evening/night
  веснћй/лљтом/ћсенью/зимћй in the spring/summer/fall/winter
Genitive (without preposition)
dates Контрћльная бџдет пїтого мђя. The quiz will be on the fifth of May.
чљрез + Accusative
an hour, day, week, etc. later чљрез чђс an hour from now
  чљрез недљлю a week from now
по + Dative
every morning, evening, night only по утрђм every morning
  по вечерђм every evening
кђждый + Accusative
every morning, day, week, etc. кђждое џтро every morning
  кђждую недљлю every week
на + Prepositional
this week, last week, next week на ітой недљле this week
  на бџдущей недљле next week
  на прћшлой недљле last week
на + Accusative
on the N th day, week, etc. на трљтий дљнь two days later
  на слљдующий дљнь next day
  на трљтью нћчь two nights later
  на слљдующий гћд next year, the following year
  на трљтий гћд two years later