Day R Survival Promo Code & Gifts are available to players from what I can find only from the developers Facebook pages. You can access the Day R Survival Promo Code option for free gifts by taping on the profile button on the main menu. I will make a list of Facebook pages and other locations for promo codes below. Be sure to check the link regularly as the developer will more than likely put more up soon.
Visit the Day R Survival Wiki & Guide for more info.
Day R Survival Promo Codes
Promo codes can expires after a short time and will no longer be good anymore so be sure to use them right away. The developers seems to have slowed down on the promo codes probably in hopes of selling more premium versions, there still may be hope though.