How long is a health check valid for?

Well it’s pretty much written out all above. I’m applying for a new job as an English teacher, and just had a health check done a few months ago. I think I heard that a health check can be used for six months after approval from the hospital, just want to see if anyone’s sure about that. Thanks.

If you have worked as an English teacher, and your work permit is still effective, you may be exempted from a health check.

If not, 3 months.

Original copy of qualified health examination regulated by the central health and welfare authority performed no more than three months prior to the application date