Скажите, пожалуйста, какое сегодня число? — Сегодня вторник, пятое марта.

In Russian, сказать basically means to say / to tell, depending on context. In questions like Скажите, пожалуйста..., it functions very naturally as a polite way to say Tell me, please... or Excuse me, could you tell me...

So Скажите, пожалуйста, какое сегодня число? is a standard polite way to ask for information.

Also, скажите is the formal/plural imperative form, so it is used:

• when speaking politely to one person
• when speaking to more than one person

That is why it sounds respectful.

Пожалуйста means please here.

So:

• Скажите = tell me / say
• пожалуйста = please

Together, Скажите, пожалуйста... is a very common polite opener, similar to:

• Please tell me...
• Could you tell me, please...
• Excuse me, could you tell me...

It softens the question and makes it more polite.

Because число means date in this context, literally number.

So:

• Какое сегодня число? = What is today’s date?
• Какой сегодня день? = What day is it today? / What day of the week is it today?

This is an important distinction:

• число asks for the calendar date
• день asks for the day

For example:

• Какое сегодня число? — Пятое марта.
• Какой сегодня день? — Вторник.

Because какое agrees with число, and число is neuter.

Russian adjectives and question words must agree with the noun in gender, number, and case.

Here:

• число = neuter singular
• so какой changes to какое

Compare:

• какой день? — day is masculine
• какая дата? — date is feminine
• какое число? — number/date is neuter

It does mean number, but in everyday Russian it is also used to mean the day number of the month, which is why it can mean date.

So Какое сегодня число? is literally something like:

• What number is today?

But idiomatically it means:

• What’s today’s date?

This is one of those expressions that is best learned as a set phrase.

Because Russian dates use a special pattern:

• the day number is an ordinal number
• the month is in the genitive case

So:

• пятое = fifth
• марта = of March

Literally, пятое марта is the fifth of March.

You cannot normally say пятый март for a date. That would not be the normal Russian way to express it.

Examples:

• первое января = the first of January
• десятое апреля = the tenth of April
• двадцать третье сентября = the twenty-third of September

Because there is an implied word: число.

When Russians say пятое марта, it is really understood as:

• пятое число марта

Since число is neuter, the ordinal must also be neuter:

• пятое

So even when число is omitted, the grammar still reflects it.

That is why dates are said like:

• первое мая
• второе июня
• третье июля

They are neuter because of the implied число.

In Russian dates, the month normally appears in the genitive after the day number.

So:

• пятое марта = the fifth of March
• десятое октября = the tenth of October

This is the standard date pattern:

• ordinal neuter + month in genitive

Some month forms:

• январь → января
• февраль → февраля
• март → марта
• апрель → апреля
• май → мая

So марта is simply the correct genitive form of март.

It does not have to. The speaker is just giving extra information.

The question:

• Какое сегодня число? asks for the date.

A minimal answer would be:

• Сегодня пятое марта. or simply
• Пятое марта.

But it is also natural to say:

• Сегодня вторник, пятое марта.

That means:

• Today is Tuesday, the fifth of March.

So the answer gives both:

• the day of the week
• the date

Because Russian often omits the verb to be in the present tense.

In English, you say:

• Today is Tuesday
• Today is the fifth of March

In Russian, in the present tense, you usually just say:

• Сегодня вторник
• Сегодня пятое марта

There is no present-tense есть here. Leaving it out is normal Russian grammar.

Because both parts act like predicate nouns/expressions after an omitted present-tense to be.

So:

• Сегодня вторник = Today is Tuesday
• Сегодня пятое марта = Today is the fifth of March

Вторник is nominative because it names what today is.

Пятое is nominative neuter because it agrees with the implied число.

Марта is genitive because months in dates take the genitive.

So the structure is:

• Сегодня + nominative day of week
• Сегодня + nominative neuter ordinal + genitive month

Yes. That is completely natural if the context is clear.

Possible answers include:

• Пятое марта.
• Сегодня пятое марта.
• Сегодня вторник, пятое марта.

Adding сегодня just makes it more explicit:

• today is...

But if someone has just asked Какое сегодня число?, then Пятое марта is enough.

Yes, it is one of the most standard and common ways.

Very natural options include:

• Какое сегодня число? = What’s today’s date?
• Скажите, пожалуйста, какое сегодня число? = more polite
• Какое сегодня число? = neutral and common

Another possible phrase is:

• Какая сегодня дата?

But Какое сегодня число? is often the more basic textbook and everyday phrasing.

They are related, but not exactly identical in feel.

• число usually focuses on the day number of the month
• дата means date more generally

So:

• Какое сегодня число? is the classic everyday question
• Какая сегодня дата? also means What’s today’s date?, but can sound a bit more formal or abstract depending on context

For a learner, Какое сегодня число? is the essential phrase to know.

Because in Russian, names of:

• months
• days of the week

are normally written with lowercase letters, unless they begin a sentence.

So:

• вторник
• март
• марата? No — careful: the correct form is марта

This is different from English, where Tuesday and March are capitalized.

A helpful stress guide is:

• Скажи́те, пожа́луйста, како́е сего́дня число́?
• Сего́дня вто́рник, пя́тое ма́рта.

A few notes:

• сего́дня has stress on -го-
• число́ has stress on the last syllable
• вто́рник has stress on the first syllable
• пя́тое has stress on пя́-
• ма́рта has stress on the first syllable

If you are reading aloud, there is usually a small pause after пожалуйста, and another small pause before пятое марта in the answer.

Yes. It gives you the basic pattern for Russian dates:

Сегодня + day of week, + ordinal neuter + month in genitive

For example:

• Сегодня понедельник, первое апреля.
• Сегодня среда, двадцать второе мая.
• Сегодня суббота, тридцатое ноября.

And if you only want the date:

• Сегодня первое апреля.
• Сегодня двадцать второе мая.

So this sentence is a very useful model for building many other date expressions.