Compare quantity to find Date

[Anonymous]

Hello,

The title is not very clearan example will be more at least I hope 😉

I encounter a problem for a column calculation Ending month forecast. I have 2 quantities my actual quantities and my forecast quantity I would like to know when (find a date or a number of months) where the sum of these 2 quantities will be equal To Qty to collect.

The Date used for the Forecast quantities (Planned Quantity) = Date_Plan.

The Date used for the actual quantities is Date.

Thank you in advance,