Looking for some help, need simple code for project

Hi dear Arduinist or Arduinista
being a harware guy i'm looking for some software help:
With the Rainbowduino(latest model out) i built a 12h clock-dial with 144 leds, thats one for each 5 min.
Now i need code that steps up one count (one led) each 5 min.
Someone outthere?? Could n't be too difficult, but writing code is not my cup.
Promise you my first proto for a helping brain.
Thanks,
Jacob

You should probably get a realtime clock (RTC) chip to track time. The Arduino is not very good at it.

void loop()
    {
    int hour, minute;

    hour = RTC.GetHour();  //  Get the hour (0-11) from the RTC chip
    minute = RTC.GetMinute();   //  Get the hour (0-11) from the RTC chip

    int ledIndex =  ((60 * hour) + minute) / 5;
    }

How bad is the time keeping ?

I was planning a project using the arduino as the clock -- but it also will have a GPS clock

If the arduino is +/- 5% or so it would be OK for this project -- else, GPS I guess

thanks for the info

if you want a software RTC try swRTC library (its an open source one).
But if you have lack of knowledge to implement something as simple as a step up counter like the one you just said, dont you think its too big a project for you ?!?
Maybe start with smaller experiments, that will give you a better insight into the things you need to implement, but with simpler approaches, to start with. NOW THAT WOULD BE REWARDING !!

ps- Talk about swapping a salame for a pig !! lol

SolarPanels:
How bad is the time keeping ?

I was planning a project using the arduino as the clock -- but it also will have a GPS clock

The Arduino might be off by minutes a day but if you correct it with GPS time once an hour or so that shouldn't be a problem.

Thank you, John

If it is only a few minutes a day I probably can correct just once a day and be OK