Good for the Day

[keng]

Maybe this question has been answered in a previous post but I cannot find anything. If I put in an offer or bid for a SHARE I have the option to select if the instruction is "good for the day" OR a longer period. However if one deals with a CFD then there is no option, all bids and offers are ONLY "good for the day" Therefore if the CFD price only reaches my execution price in 20 trading days, I must capture the same request 20 times. Does anyone know why?