In EXOS, you can see the last up/down dates at the top of the
code:show port X info detail
command:
# show port 12 info det
Port: 12
Virtual-router: VR-Default
Type: UTP
Random Early drop: Unsupported
Admin state: Enabled with auto-speed sensing auto-duplex
Link State: Ready
Link Ups: 2 Last: Mon Oct 30 05:32:11 2017
Link Downs: 2 Last: Tue Nov 14 10:26:57 2017
....
EDIT: Brandon's answer above is better than mine.