Samsung

My phone automatically changed time with the daylight savings as it was supposed to until last night when it decided that it wanted to revert to an hour ahead. I tried to manually change the time and it says that I can only do so when operating on an analog network. After a few hours it went back to the correct time but I did find it a bit annoying. Has anyone else had this problem? Any idea what I should do to keep myself from believing that I have lost an hour?