### 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: However, it is not regular enough to accurately predict. The tolerance of about one week needs to be prepared in advance, and sometimes it will overturn if it is unlucky (suddenly several days in advance).
### Errors: There is a major error of incorrect translation is missing content from the correct translation at "However, it is not regular enough to accurately predict.". There is a major error of incorrect translation has stylistic problems at "and sometimes it will overturn if it is unlucky (suddenly several days in advance).". There is a minor error of problems with grammar, other than orthography at "it is unlucky (suddenly several days 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.