periodic weekly

If we have tenancies which have weekly payments, the 6 months have gone and we are
now in periodic (ast) if for example the tenancy started 25th of the month, what datedo we give notice and when does it end if we want to give notice this month. Is the
statutory notice weekly or monthly if weekly the what date, if we cant do weekly let me know (it says weekly payments in tenancy)

Our rent period is Monday to Sunday each week. The tenancy has always been weekly 6
months fixed as ast

Thanks