Raspberry Pi Real Time Clock Module - Auto Set Date & Time On System Boot
The full write up for this project can be found at:
http://www.newsdownload.co.uk/pages/R...
Very low power clock module which maintains the system time and date on the Raspberry Pi while it is powered off. Run from a single button cell to last up to ten years. Can be used with Linux distributions such as Raspbian, Arch Linux or OpenElec XBMC media player.