TimeRTC
From: https://github.com/thijse/Arduino-Code-and-Libraries/blob/master/Libraries/Time/Examples/TimeRTC/TimeRTC.pde
/*H*******************************************************
* TimeRTC.pde
* example code illustrating Time library with Real Time Clock.
********************************************************/
#include <Time.h>  
#include <Wire.h>  
#include <DS1307RTC.h>  // a basic DS1307 library that returns time as a time_t

//************************* DEFINES ************************************

//************************* PROTOTYPES ************************************

//************************* VARIABLES ************************************

/*F********************************************************************
*
**********************************************************************/
void 
setup()  
{
    Serial.begin( 9600 );
    setSyncProvider( RTC.get );   // the function to get the time from the RTC
    if( timeStatus()!= timeSet ) 
        Serial.println( "Unable to sync with the RTC" );
    else
        Serial.println( "RTC has set the system time" );      
}
/*F********************************************************************
*
**********************************************************************/
void 
loop()
{
    digitalClockDisplay();  
    delay( 1000 );
}
/*F********************************************************************
* digital clock display of the time
**********************************************************************/
void 
digitalClockDisplay()
{
    Serial.print( hour() );
    printDigits( minute() );
    printDigits( second() );
    Serial.print( " " );
    Serial.print( day() );
    Serial.print( " " );
    Serial.print( month() );
    Serial.print( " " );
    Serial.print( year() ); 
    Serial.println(); 
}
/*F********************************************************************
* digital clock display: prints preceding colon and leading 0
**********************************************************************/
void 
printDigits( int digits )
{
    Serial.print( ":" );
    if( digits < 10 )
        Serial.print( '0' );
    Serial.print( digits );
}