Yep. It's not hard, once you know what you are doing. Like Excel, Numbers has a Fill feature.
Enter your first date in the beginning cell.
Exit the cell editor.
Tap the cell to select it and get the pop-up menu.
Choose Fill.
A yellow box with highlight the cell.
Drag the edge of the box either vertically or horizontally to start filling.
This defaults to single increment fills. If you want to fill, say by day of the weak, create the first two cells with the right increment. Select them both (by by dragging the dots when after selecting the first cell); Then select Fill from the pop-up menu and continue as before.
Fill also works with numbers and text (with some limitations).
Don't forget that you've got built in Help in Numbers. Tap the wrench icon and choose Help. The instructions for Fill (briefer but illustrated) are under the Enter data into a table cell chapter.
