Now you only need to replace #channel with the correct name once...
Code:
on 1:text:!tban *:#Channel:{
  if ($2 !ison $chan) notice $nick $2 is not on $chan
  elseif (($3 !isnum 0-) && ($3 != $null)) notice $nick Invalid format. Use !tban <nick> [wait-time]
  else $iif($calc(0 + $3),.timer 1 $v1) ban -ku600 $chan $2 2
  }
}