### Chinese: 但也不是规律到能精准预测，大概一周左右的公差，需要提前准备，有时候运气差也会翻车（突然提前好几天）。
### English: But it is not regular enough to be able to predict accurately. The tolerance of about a week needs to be prepared in advance, and sometimes bad luck will turn over (suddenly several days in advance).
### Errors: There is a major error at "The". There is a major error at "tolerance of". There is a major error at "needs to be prepared". There is a major error at "bad luck will turn over (suddenly several". There is a major error at "in advance".

### Improved English: But it is not so regular that you can precisely predict it; there is a difference of around a week; you need to prepare early and sometimes you may get unlucky and it arrives several days earlier.