not feeding whole day?

[whenwill]

any one know how many hours can I not bf for and still keep supply that is enough for dd at 7.5 months?

Do you mean you will be away from baby every day or just as a one off? Has she already reached 7.5 months or are you thinking of the future? When I had to leave my children at about this age, I wasn't comfortable with leaving them without boob for more than say 4 hours, if I remember right.
You can do an experiment- just leave baby with dad or whoever and go out shopping for clothes. Keep on the end of the phone and get updates about how they seem to be doing, then go back when it seems like baby just can't cope without bf a minute longer. You might be surprised how well they manage and suddenly get a lot more interested than before in their porridge/ water cup etc. No need to worry about supply at all!

It'll depend entirely on how much you're feeding her by then. If she's still having two or three feeds during the day and you're leaving her regularly then you'll need to pump at those times to keep your supply up. If it's just a one-off you should be ok (though will probably have to express a bit to keep yourself comfortable).

thanks for response this is the background:
www.mumsnet.com/Talk/breast_and_bottle_feeding/1562396-how-long-can-i-go-between-feeds

so really i mean working towards just not feeding in day. apparently nursery ebf babies do it but not sure if for so many hours? no hope of nights improving if i do it though i suppose.