diagrams: invert xaxis

[dberardo-com]

very often i am using spreadsheets to visualize temporal data. as humans we think from top to bottom, so today would be on top and 7 days ago would be on the bottom.

but this is hard to visualize in the spreadsheet becasue (as of version 16) there is no x-axis inversion option and i end up with an spreadsheet that look like this:

bu then a diagram that looks like this:

where you can of course see that the x-axis should go from left to right and not viceversa.