In financial models, data typically flows Left to Right (Jan $\rightarrow$ Dec).

Type the desired "Left" part in the cell next to your first data point. Press .

Below is a blog post draft that covers both the technical shortcut and the business template.

| Mistake | Why It Happens | Fix | | :--- | :--- | :--- | | | You dragged a formula with relative references (e.g., =A1 becomes =B1 ). | Use Fill Formatting Only instead of standard drag. | | Borders disappear | You copied over cells with existing left/right borders. | Clear formats first: Home > Clear > Clear Formats . | | Dates change | Excel auto-increments months/days. | Hold Ctrl while dragging to copy exact date instead of series. |