In that case, still enable the
Show last scan and last seen time option highlighted in the screen shot above, and optionally export the configuration to a file. Use that configuration file with your command-line scanning, and the 'Last scan' column will essentially be the time stamp:
netscan.exe /auto:"z:\output.csv" /config:z:\last-scan-on.xml
The output will be like this:
"IP Address","MAC Address","Response Time","Host Name","Last Scan","Last Seen"
"192.168.0.1","AC-9E-07-7F-A2-F0","1 ms","RT-AC68U","24/09/2020 9:40:58 AM","24/09/2020 9:40:58 AM"
"192.168.0.8","B4-01-62-13-2D-DF","3 ms","VM-2","24/09/2020 9:41:10 AM","24/09/2020 9:41:10 AM"
It is possible to have a different time stamp type, e.g. UNIX time. If that's the case, let me know and I will explain how to do that.