#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd = LiquidCrystal_I2C(0x27,16,2);
#include <TimeLib.h>
const int btnForward = 2; 
const int btnBack = 3; 
 
unsigned long prevtime;
void setup()
{
 Serial.begin(9600);
 digitalWrite(btnForward, HIGH); 
 digitalWrite(btnBack, HIGH);
 lcd.init();
 lcd.backlight();
 lcd.blink();
 setTime(8,50,0,28,12,23);

}      
void loop()
{
   prevtime = now(); 
 while( prevtime == now() ) 
 {
 
 if(checkSetTime())
 prevtime = now(); 
 }

 digitalClockDisplayLcd();
 delay(1000);
 
}
boolean checkSetTime()
{
int step;  
boolean isTimeAdjusted = false; 
 step = 1; 
 while(digitalRead(btnForward)== LOW)
 {
 adjustTime(step);
 isTimeAdjusted = true; 
 step = step + 1; 
 digitalClockDisplayLcd();
 delay(100); 
 }
 step = -1; 
 while(digitalRead(btnBack)== LOW)
 {
 adjustTime(step);
 isTimeAdjusted = true; 
 step = step - 1; 
 digitalClockDisplayLcd(); 
 delay(100); 
 }
 return isTimeAdjusted; 
}

void digitalClockDisplayLcd(){
 
 lcd.setCursor(0,0);
 lcd.print(hour()); 
 
 printDigits(minute());
 printDigits(second()); 
 

 lcd.setCursor(0,1);
 lcd.print(day());
 lcd.print(" ");
 lcd.print(month());
 lcd.print(" ");
 lcd.print(year());
 
}
void printDigits(int digits){

 lcd.print(":");
 if(digits < 10)
 lcd.print('0');
 lcd.print(digits);
 
}