【求助】应助 突然想不明白BY的意思了，求助下

由8/1 开始, 当然包括8/1.

That day (8/1) is included.

= = = = = =
by = not later than

Example : Please return the books by next Friday = The books should be returned on next Wednesday, Thursday or even Friday, but not later than Friday (i.e. not on next Saturday)

I suggest that“with effective from 2009/8/1”is better than “by 2009/8/1”for this particular sentence.

谢谢谢谢

非常感谢

学习了，这些中学学的都忘了

这些意思，如果在一些场合突然看到，还真是会被搞懵的。