NOOOOOOOOOOOOOOOOOOOOO. Reverse them or just leave the light on 24 hr/d. Look through these forum for more basic grow info cause if you didn't know or look for that yet, you are not ready to grow. Make sure everything is set up right before strating the grow.
The HPS is amazing for flowering but I have never personally vegged underneath one. I always use flouros. You can pick up some flouros for very cheap and keep them close to the plants and they will shoot up really quick. Are you growing from seed or clone?
Also, how many plants are we talking here because a 1000w HPS is pretty serious and even if you do use it for veg, you may have to start it a lil higher than that because of the heat. What type of ventilation do you have cause just a regular fan isn't good enough to keep that cool?