I am assuming that you are talking about the Annual Meeting of the Parish Council and not the Annual Parish Meeting. In which case:
The law says that three clear days at least before a meeting of a parish council ‘a summons to attend the meeting, specifying the business proposed to be transacted at the meeting and signed by the proper officer of the council, shall be left at or sent by post to the usual place of residence of every member of the council.’ (Local Government Act 1972, c.70, Schedule 12, Pt 2, Para 10(2)(b))
It is unlawful for the Parish Council to make a decision, especially a decision to spend money, without sufficient notice.
The Transparency Code for Smaller Authorities (December 2014) says that ‘smaller authorities should ... publish meeting agendas, which are as full and informative as possible, and associated meeting papers not later then three clear days before the meeting to which they relate is taking place. (Para. 30).