"Three times a week" in Engpsh is a common phrase used to indicate the frequency of an event happening three times in a seven-day period.
Source: The concept of a "week" is widely used and recognized globally, and the phrase "a week" typically refers to a seven-day period. The use of "three times" is a way to express frequency in Engpsh.
Examples:
I go to the gym three times a week.
(我每周去健身房三次。)
She takes a dance class three times a week.
(她每周上三次舞蹈课。)
We have a team meeting three times a week.
(我们每周有三次团队会议。)