What is the solution for the date/time error on iPhone 5c?

I just recently got an iPhone 5c, and it works amazing it's basically brand new out-of-the-box. But for the life of me, I can't figure out why the date and time is off. I've tried both bowl resets and I've tried going into date and time settings to reset it. I've tried going back-and-forth between manual and automatic detection, but nothing seems to be working. Someone please help me.

Try removing sim card then put back in

I had a 5c about a year ago with a similar issue. It looks like it is a hardware issue that can't be easily fixed.

Just to confirm, does this issue happen when you put the phone to sleep? As in you set the correct time and while you are using the phone the time is fine, but when you put it to sleep, the clock changes?