Quoting from [qianshou]:
will it be treated not honest?
Documents such as drafts, certificates, declarations, statements, transport documents and
insurance documents must be dated and signed. Whether other documents require dating
will depend on the nature and content of the document in question. A requirement for a
document to be dated - other than those mentioned above - may be satisfied by linkage
within its content to the date of another document forming part of the same presentation
(e.g. where a shipping certificate will be issued which states “date as per bill of lading
number xxx” or similar).