Number + 月
月 (yuè) means "month" and is used after a number to indicate a specific month of the year, such as 一月 (January) or 二月 (February). It also appears in classical poetry where it can poetically refer to the moon or a time of year.
我的生日在三月。
Wǒ de shēngrì zài sān yuè.
My birthday is in March.
一月是一年的第一个月。
Yī yuè shì yì nián de dì yī ge yuè.
January is the first month of the year.
他打算七月去日本旅行。
Tā dǎsuàn qī yuè qù Rìběn lǚxíng.
He plans to travel to Japan in July.