A nice thing about that version is that it keeps track of previous
uptimes.
My current M-x uptimes shows only 2 days but the top 10 uptimes
display shows a 61 days long session and a bunch of others that lasted
over a month.
One month seems to be as long as I usually manage to go without
wanting to make a change that would be just too difficult to do
without rebooting Emacs. Upgrading a complicated elisp package that
cannot be easily unloaded for example. There is also the occasional
Emacs crash and problems with the underlying OS or hardware.