One week is the first week of school, the third week is odd weeks, the second week is two weeks, and the fourth week is even weeks.

The second week of formal class means that the first week is administrative week, which is used for other purposes.

Some courses are taught alternately once a week and twice a week. One class this week and the next next next week. There is plenty of time and credit line, neither more nor less.

Extended data

There are 365 days in a year, which means there are 52 weeks. One week is the first week after New Year's Day, two weeks is the second week, and the third week is still one week. And so on.

In different countries, the start time of a week is not exactly the same. For example, many English-speaking countries, Judaism and Japan begin on Sunday, while Egypt Week begins on Saturday.

Most European countries regard Monday as the first day of the week. Chinese mainland once thought that Monday was the time to start.