Hi,
You can use the AT command with the following syntax
AT [\\computername] time [/INTERACTIVE]
[ /EVERY:date[,...] | /NEXT:date[,...]] "command"
so your command would be
at 20:00 /every:m, t, w, th, f, s, su "your command"
Note, is you are typing this on the target server then you do not need the [\\computername] option. Also the schedule server needs to be running.
Bye.