This is a mysterious one. Ever since I got myself an iPhone 4, my original iPhone 3GS has been sent to semi-retirement. I occassionally use it, especially when my iPhone 4 is plugged to the wall socket and charging.
During a two-weeks trip to Australia, I brought my iPhone 3GS in the luggage as backup. And in order to conserve battery power, I decided to turn the device off instead of having it drip battery juice by sleeping. I never needed the iPhone 3GS throughout the trip. So, when I came back home, I powered the device back on. It worked like normal. It’d even sync with iTunes like normal. However, one thing was wrong until I realize it later. The date and time has been reset back to 1970.
I noticed the very same issue with my iPod touch as well. It was reset back to the same date and time in 1970. I guess this warrants an investigation.
A simple search across the internet made me realize that the battery may possibly be failing. It may seem very true for the iPod touch, which is about 2 years old now. However, my iPhone 3GS just passed its one year old birthday about five months back. I guess it all depends a lot on your usage pattern. As I have outlined before in my post regarding how I took care of batteries across all my rechargeable devices, this shouldn’t have happened, at least for the iPhone 3GS.
I’m still puzzled, but I’d rest my case that the battery on both devices are really dying.