Hi All - I am having a problem finding a formula that returns a count in a delivery cycle. I have a four week delivery cycle and wish to count weeks to the warehouse next delivery. Week to week.xlsx

Each coloured tab is a warehouse. In each tab D3 is the 'Delivery Week', D4 is where I would like to return how many weeks it is to the next delivery. I am using 'Del Week LU' to as the look up sheet to find which Delivery Week I am currently on. It is easy to get the delivery week I am on but I am pulling ,the little bit, of hair I have out trying to get a return of the number of weeks to the next delivery.

Is there a formula I could use or do I have to run a table with a look up.

Many thanks in advance

David