a working day的用法和样例：
- In this project calendar, every day of the week is a working day.
- This Sunday is a working day, I have to work yet another day.
- A working day means a day other than a public holiday (in the United Kingdom), Saturday or Sunday.
- Refers in a working day, any contact does not have to surpass 15 minutes weighted average allows the contact level.
- The unions are campaigning for a shorter working day.