I road corn in the morning and afternoon just before I get in the stand. A lot of times, deer are already on it after I park my truck and walk to the stand. If you road corn at night, deer will just eat it that night.
Deer are a lot less afraid in the dark. You might spook them a little but they won't go far. Been road corning here for 18 years and my deer are use to it, in fact the sound of the road feeder brings them in. I corn just before daylight, if I corn too early the deer will come in and eat all the corn before daylight.