Work at least four calendar days per week.

每周至少实习四个日历天。

Days refers to 24-hour periods, not calendar days.

天指的是24小时的阶段，不是日历日。

The new directive extends this to 14 calendar days.

新法令将期限延长至14天。

Construction time was slashed from 540 to 390 calendar days.

时间是从540天削减至390天。

To ensure total construction period to meet 595 calendar days.

确保工程总工期目标：595个日历天。