### 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 so regular that it can be accurately predicted. The <v>travel</v> time is about a week, so it needs to be prepared in advance. Sometimes, it won't follow the schedule due to bad luck (suddenly several days ahead).
### Errors: There is a minor style/awkward error at "travel" within <v></v>.

### 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.
