My S3 has been displaying the wrong time lately; maybe 3 or 4 times in the last week. It's not off by exactly an hour, so I know it's not a timezone or daylight-saving-time issue. It's usually off by 15 to 25 minutes; just enough to make me late to work.

It's not only a 3rd-party app or widget issue; the actual phone time is wrong (in the upper, right-hand corner near the signal indicator).

My wife has an older Samsung Galaxy Nexus, and this never happens on her phone. We live together (obviously), so our phones are in the same location, and we use the same provider; so I don't think it's a network/signal/tower issue.

Any ideas what would cause this. I've searched around, and all I can find are forums w/ 6 pages of "Me too" responses. A couple definitive answers/suggestions would be welcome.

UPDATE - I've disabled the automatic date/time settings, but the problem still comes back. I've worked on desktops and laptops for years, and they all use a CMOS battery to keep track of time... even when a computer is off. Do phones have anything similar?