Signature and date are the necessary conditions for writing a will, and a will without the necessary conditions is generally invalid.

Legal basis:

Article 17, paragraph 2, of the Inheritance Law: A self-made will is written by the testator, signed and marked with the year, month and day.

Exceptions:

If a self-made will was made before the implementation of the Inheritance Law (1985 10 1), and the contents are legal, and there is sufficient evidence to prove that it is the true intention of the testator, the will can be considered valid.

The legal basis for the exception:

Article 35 of the Judicial Interpretation of < Inheritance Law >: A will made before the implementation of the Inheritance Law is slightly deficient in form, and its contents are legal. If there is sufficient evidence to clearly show the true intention of the testator, it can be considered as valid.