In my opinion a 9:30 pm feeding is too late for a pup his age but I guess in your situation is can not be avoided. Also, twelve hour in between feedings is way too long. Pups this age can get low blood sugar and go into hypoglycemia shock from not eating. As a breeder myself I have my pups on an every 6 hr feeding 3 times a day. Than I instruct them to stretch it out by the age of 12 months of age to get them to a twice a day feedings. Keep in mind the early you feed them their final meal for the day and restrict water intake the longer they will have to empty their bowels and urinate before settling down for the night. That way you can avoid any accidents or need for late night potty breaks.
I've had much success potty training my pups and have taken the time to post it to share with others. You can find tips on training, grooming and other useful tips on my web page.
www.dawnsyorkies.weebly.com/training-tips