Learn Italian: Oggi è il quattro maggio.

In Italian, dates use regular counting numbers (like two, three, and four), rather than ordinal numbers (words that show position in a list, like second, third, and fourth). The single exception is the first day of the month, which uses il primo (the first). For all other days, like May 4th, you literally say the four May.

Why is there an il before the number?

When giving a date, Italian requires the masculine singular article il (the) right before the number. You can think of it as saying the four of May.

Why is maggio written with a lowercase letter?

Unlike in English, months of the year are not capitalized in Italian unless they appear at the very beginning of a sentence. The same lowercase rule applies to days of the week.

Do I need a word for of between the number and the month?

It is completely optional. While you might sometimes hear people use di to say il quattro di maggio, it is much more common to just place the number directly before the month, exactly as it is shown in this sentence.