UK Landlord Forum / Life

Hello all. Re signing and dating an AST, with a guarantor, could you please advise if there is a particular order of signing by the parties in order to make it legal? Guarantor first or at the end? The tenants will move in on 30 May so I propose to date the AST 30 May but can I get everybody to sign before the date and date each signature on the date signed? Thank you very much for your help