GrammarDates (calendar)

When talking about the calendar and dates, there are a few small pieces: the day of the week, the day of the month, the month and the year. Each piece has its own little rule, and there is also a little case rule for the whole date.

Days of the week

First, the seven days. Note their gender, it matters for the “on …” form.

Today is Monday uses the plain nominative: Сего́дня понеде́льник.

To say “on Monday”, use в + accusative. For the masculine days the accusative looks identical to the nominative; the feminine days change their ending -а → -у. For вто́рник the preposition becomes во for easier pronunciation.

Every Monday or “on Mondays”, use по + the dative plural instead:

• Я хожу́ в бассе́йн по понеде́льникам. (I go to the pool on Mondays.)
• Магази́н закры́т по воскресе́ньям. (The shop is closed on Sundays.)
• По суббо́там мы отдыха́ем. (On Saturdays we relax.)

Months

The twelve months are all masculine. You will meet them in two forms: the genitive (used inside a date, “the tenth of March”) and the prepositional after в (“in March”).

To say simply “in March”, use в + prepositional:

• У меня́ день рожде́ния в ма́е. (My birthday is in May.)
• Мы бы́ли в Москве́ в декабре́. (We were in Moscow in December.)

Notice that months use в + prepositional, while days of the week use в + accusative. Same preposition, different case — because the underlying idea is “within the month” but “on the day”.

The full calendar date

A date joins an ordinal number in the neuter with the month in the genitive. The ordinal number is for the day (“the 10th“), the genitive month means “of …”:

деся́тое (the tenth) + ма́рта (of March) = деся́тое ма́рта (the tenth of March)

Here are the ordinals you need for the days 1–31. Only the last word ever changes; the day-of-month is always neuter (-ое / -ье):

“Today is …”

When the date is the answer to “what is the date?”, the ordinal stays in the plain nominative neuter and the month stays in the genitive throughout:

• Сего́дня пе́рвое сентября́. (Today is the first of September.)
• Вчера́ бы́ло три́дцать пе́рвое декабря́. (Yesterday was the 31st of December.)
• За́втра бу́дет восьмо́е ма́рта. (Tomorrow will be the 8th of March.)

“On …”

When something happens on a date, put the ordinal into the genitive too (neuter genitive ends in -ого / -его). There is no preposition, the genitive alone means “on”:

• Экза́мен пя́того ию́ня. (The exam is on the fifth of June.)
• Она́ родила́сь двена́дцатого апре́ля. (She was born on the twelfth of April.)
• Уви́димся пе́рвого сентября́. (See you on the first of September.)

Years

A Russian year is also an ordinal number — “the two-thousand-twenty-sixth year”, not “two thousand twenty-six”. As with any long compound ordinal, only the last word declines; everything before it stays as a plain cardinal number.

две ты́сячи два́дцать шесто́й год (2026, “the 2026th year”)

The bare year, as a label, is nominative with год: Сейча́с две ты́сячи два́дцать шесто́й год. (It is now 2026.) But in real sentences the year usually appears in one of two forms.

“In 2026” — в … году́

To say something happened in a year, use в + the prepositional, and the word год takes its prepositional ending году́:

• Я роди́лся в две ты́сячи пе́рвом году́. (I was born in 2001.)
• Э́то случи́лось в ты́сяча девятьсо́т девяно́сто пя́том году́. (That happened in 1995.)

Only the final ordinal changes to the prepositional (-ом / -ем): шесто́й → в … шесто́м году́.

“The 10th of March 2026” — the year goes genitive

When a full day-month-year date is given, the year drops into the genitive and its год becomes го́да. Think of it as “the tenth of March of the 2026th year”:

• Сего́дня деся́тое ма́рта две ты́сячи два́дцать шесто́го го́да. (Today is the 10th of March 2026.)
• Он прие́хал деся́того ма́рта две ты́сячи два́дцать шесто́го го́да. (He arrived on the 10th of March 2026.)

So in a spoken full date, the day carries the nominative-vs-genitive contrast (“is” vs “on”), while the month and year sit in the genitive as “of March, of the 2026th year”.

Decades and centuries

Centuries use the ordinal + век (century), and are usually written with a Roman numeral. “In the …th century” is в + prepositional:

• Мы живём в двадца́ть пе́рвом ве́ке (We live in the 21st century) — written в XXI ве́ке.
• Пу́шкин жил в девятна́дцатом ве́ке. (Pushkin lived in the 19th century.)

Decades like “in the nineties” use the ordinal in the prepositional plural with го́ды / года́х (years):

• В девяно́стых года́х всё измени́лось. (Everything changed in the nineties.)
• Э́та му́зыка из шестидеся́тых. (This music is from the sixties.)

From … to … (spans of dates)

To give a range, Russian pairs prepositions. The most common are с … до and с … по. After с and до everything is genitive; after по the endpoint is accusative and is felt as inclusive:

• Магази́н рабо́тает с понеде́льника до пя́тницы. (The shop is open from Monday to Friday.)
• О́тпуск с пе́рвого до деся́того ию́ля. (Holiday from the 1st to the 10th of July.)
• Ку́рсы с пе́рвого сентября́ по три́дцать пе́рвое ма́я. (Courses from 1 September through 31 May.)

Asking about dates

Finally, the question words. Which one you choose mirrors the “is” vs “on” contrast from above:

• Како́е сего́дня число́? — Двадца́тое ию́ля. (What’s today’s date? — The 20th of July.)
• Како́го числа́ ты прие́дешь? — Пятна́дцатого. (On what date will you arrive? — On the 15th.)
• В како́м году́ ты родила́сь? — В две ты́сячи пе́рвом. (What year were you born? — In 2001.)

Quick reference

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See also: for the clock (“at three o’clock”, “half past six”) see telling the time, and for the endings and stress of the numbers themselves see ordinal numbers.