When do American immigrants apply for Form 458? Can they only apply when the timetable expires?

Yes, you need to wait until the end of the scheduled time to apply and review.

The schedule of American immigration 458 is as follows:

Every month, the State Council publishes the latest immigration schedule, usually in the middle of the month. The effective date of the newly announced immigration schedule is 1 day next month (for example, the effective date of the immigration schedule announced by the State Council on September 9th is 10- 15). According to the use of immigration quota, the priority date of different types of professional immigrants in different countries may change differently every month. So learn how to look at the timetable of American professional immigrants.

Immigrants queue up according to "country of birth" to decide whether their status can be adjusted.

The country of birth of the spouse can also be used to decide whether to apply for a change of identity (I-485). For example, the principal applicant was born in China, but the spouse's country of birth is France, and the person born in China now has an appointment, but the person born in France has no appointment, so both the principal applicant and the spouse can apply for I-485 according to the appointment of the spouse's country of birth.

The principal applicant can only benefit from the spouse's country of birth, but not the child's country of birth. For example, if both the principal applicant and the spouse were born in China, although the child was born in the UK and the current timetable in the UK is current, the principal applicant cannot submit an I-485 application in the child's country of birth, and still has to wait for the timetable of his or her spouse's country of birth.