Show stacking and show history timestamp
Beginning with software release 15.18, the 2920 switch displays the
show stacking
command twice and an entry with a blank space after entering the
show history timestamp
command. For example:
switch# show history timestamp 3 Wed July 25 2015 07:00:51 show stacking 2 Wed July 25 2015 07:59:31 show stacking 1 Wed July 25 2015 07:59:35 switch#
Note that this is expected behavior.