Regular Hours:Remember these facts about the suns rays: The suns rays are the strongest between 10:00a.m. and 4:00p.m. Try to keep your baby out of the sun during these hours. The suns damaging UV rays can bounce back from sand, snow, or concrete; so be particularly careful in these areas. Most of the suns rays can come through the clouds on an overcast day: so use sun protection even on cloudy days.