Comments
Some of our data is lagging by more than a couple months behind other sources. To make updates work automatically, in the source of current value, I specify a range in the past to pull in. I use a year's worth of data, so I add conditions that the consumption end date "Last x months" = 15 and also "Older than x months" = 3. That way it avoids dates for which we don't have data yet, but it also automatically pulls in new data each month.
A sales agreement is typically a long-term contract with a customer who commits to buy a certain volume at a certain price over a certain period of time. It has only 2 dates: the effective (start) date and the expiration (end) date. You can easily plan the fulfilment of sales agreements by creating demand forecasts, or set up a production or purchase plan as a supply forecast to build up inventory at the times that suit your business. I don't really see the need for another planning tool.