1. Drag the Fill Handle of a single cell to copy that cell. The Fill Handle is at the bottom right of any selected cell or group of cells. 2. Drag the Fill Handle of a cell containing January, Jan, ...
Q. In the past, I could enter 1/31/2019 in cell B1 and 2/28/2019 in cell C1, highlight both cells, and then drag the Fill Handle to the right to generate the headings 3/31/2019, 4/30/2019, 5/31/2019, ...