Proper nouns name things. A proper noun is always capitalized. Names of the days of the week are proper nouns. Days of the week should always be capitalized.
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
I have softball practice on Thursday, and we play in a tournament on Saturday.
Always capitalize the days of the week because the days of the week are proper nouns.
▶It’s your turn. Find the proper nouns in this sentence: I have a science test on monday, and my lab report is due on friday. Did you find two days of the week? Did you capitalize them? Good for you!