On one RPi I am using a GPS module. I need to add support for its PPS signal for more accurate time keeping.

> On Jul 7, 2014, at 7:39 AM, Skip Tavakkolian <skip.tavakkolian@gmail.com> wrote:
> 
> there are RTC modules for the pi (talk over i2c, based on DS1307 or DS3231). i use them with linux distro's and they seem to work fine.
> 
> 
> 
>> On Mon, Jul 7, 2014 at 6:59 AM, Richard Miller <9fans@hamnavoe.com> wrote:
>> > By the way, how I can arrage the correct time in this system?
>> > I don't mean the /adm/timezone/local, because
>> > in the usual PC, we can change it at BIOS screen.
>> 
>> Unlike a PC, the raspberry pi doesn't have a battery-backed
>> real time clock.  If you configure a kernel without the 'fakertc'
>> device, it will prompt you to enter the time and date when you
>> power on.  For me this was too annoying, which is why I made the
>> fakertc device.  With a network connection, the time should be
>> corrected by aux/timesync soon after booting.
>