I recently moved across the country. What would make my wifi iPad think it is in the new location sometimes and in the old location sometimes?

I am always connecting to the same router at home. It seemed to get registered with the Apple database within a day or two after I moved, and my iPad recognized that it was in the new location. However, during the night each night, my iPad flips back to the old location and the time zone changes. By the time I get home from work in the evening, the location is correct again.