You could just check the time and say if its between these times then call another command, and if not then don't do anything. Edit: something like this:
define CheckTime {
set(#hour,$plugin function("DateTime Manipulation.dll", "$datetime manipulation", $date, "UBOT", "HH", "en-US", "en-US"),"Global")
if($both($comparison(#hour,">= Greater than or equal to",8),$comparison(#hour,"<= Less than or equal to",18))) {
then {
MyCommand()
}
else {
}
}
}