No, the word ‘night’ is not a proper noun. It is a common noun that refers to the period of time after sunset and before sunrise, when it is dark outside.
Proper nouns are specific names of people, places, organizations, or sometimes things, and they are always capitalized. For example, ‘Monday’ is a proper noun because it refers to a specific day of the week, while ‘day’ is a common noun. In contrast, ‘night’ does not refer to a specific night or event, but rather a general time period, so it remains a common noun. However, if ‘Night’ is used in a specific context, such as in the title of a book or a movie, it may be capitalized as part of that title, but that does not change its status as a common noun.