Resource curves shouldn't require a PhD in spreadsheet gymnastics. The user who posted this is asking a deceptively simple question: how do you take hours, split them across a timeline with two overlapping durations, and apply a curve? The answer is yes, this can be built. And the fact that they're asking suggests they've already hit the wall that traditional spreadsheets put in front of anyone trying to model real-world resource allocation.
What they're describing is a two-ended timeline problem. Duration A runs forward from the start. Duration B runs backward from the end. Duration A+B is the full span. The hours need to be distributed across months using a curve like 10/90 or 30/70, and then adjusted for monthly capacity differences like 160 hours versus 200. This is exactly the kind of logic that a fixed grid of cells fights against. In a legacy spreadsheet, you'd need helper columns, conditional formulas, and manual cross-checks to handle the backward duration alone. The user is right to sense that there should be a cleaner way.
The practical path forward is to stop thinking in terms of cell references and start thinking in terms of variables. Define start date, duration A, and duration B as inputs. Let the tool calculate the end date. Define the hour total for each resource. Then let the system spread those hours across the months using the selected curve, respecting that Duration A and Duration B are additive but not symmetrical. The super stretch goal, adjusting for months with different working hour totals, is not a stretch at all. It's a lookup table and a proportional allocation. The hard part is the structure, and the structure is what spreadsheets don't give you for free.
This user is on the right track because they're describing a model, not a formula. They want the tool to understand that a resource curve has shape, direction, and capacity constraints. That's not a spreadsheet problem. That's a data modeling problem that spreadsheets were never designed to solve. The good news is that the tool they're envisioning is entirely buildable with the right approach. Start with the variables, build the timeline logic, then layer on the curves and capacity adjustments. Each step is modular. Each step removes a manual headache. The user should stop trying to force this into a grid and start building the logic that the grid should have had from the beginning.