Default file open/save sort by modified?

Solution 1:

Take a look at the file ~/.config/gtk-2.0/gtkfilechooser.ini. You should see something like this:

[Filechooser Settings]
LocationMode=filename-entry
ShowHidden=true
ExpandFolders=true
ShowSizeColumn=true
GeometryX=2064
GeometryY=1053
GeometryWidth=768
GeometryHeight=638
SortColumn=name
SortOrder=ascending

Change SortColumn=name to SortColumn=modified.

I found out about this file from this launchpad issue, although there the author states that changing the setting there did not work for him. It does work for me, whereas making the change in dconf-editor does not. This also answers How do I set the default sort order in open file dialog to “Name”?, but I do not have sufficient reputation to answer it there.