Average x function combined with date table

hi all,   i have two tables:   Datetable   Date Isworkingday 24-5-2024 1 25-05-2024 0 26-05-2024 0 27-05-2024 1 28-05-2024 1 29-05-2024 1 30-05-2024 1 31-05-2...