Existem algumas opções que você pode combinar.
A opção -c classifica por hora modificada [1]:
-c with -lt: sort by, and show, ctime (time of last modification of file status information) with -l: show ctime and sort by name otherwise:
sort by ctime
As opções -u e -t também podem ser usadas:
-t sort by modification time
-u with -lt: sort by, and show, access time with -l: show access time and sort by name otherwise: sort by access time
Você pode colocar tudo junto assim [2]:
ls -ltcr # sort by and show change time, most recent last
ls -ltur # sort by and show access time, most recent last
ls -ltr # sort by date, most recent last
[1] link
[2] -r inverte a ordem