This is the 2889th most frequent Chinese word.
星期三
Wednesday
Here, '星期三' refers to a regular day of the week within a recurring event or habit.
星期三的时候，我常常锻炼身体。
I often exercise on Wednesdays.
The word '星期三' is used here as the name of the day of the week.
今天是星期三。
Today is Wednesday.
In this sentence, '星期三' is indicating the specific day when the action will take place.