有效期自签字日起5年 英文怎么说？

it's valid for 5 years since signed

It shall enter into force on the day of signature and be valid for five years.

自签字之日起生效，有效期5年。

有效期自签字日起5年
Since the signature is valid from the date of 5 years

The period of validity is five years and begins form signature date.

Valid for 5 years from the date of signature.

The valid period is 5 years since the date of signature.