Same issue. Have to set date time every time camera is turned on. Here is what I found. When I put in a new cr1220 battery, even though it only fits in one way, I inserted it upside down. I only noticed this after reading this forum and noticing that the closure for the battery didn't set flush with the camera. I took it out, flipped it around and inserted it again and it did go in flush with the camera. Turned it on, reset date and time, turned it off and back on again and danced if it didn't hold my date:time.