Programming the DS1307

Would some one help me out? I am trying to put together some code that will enable me to reset a DS1307 RTC using an LCD which has four twenty character lines. Below is part of a sketch I downloaded. As it stands you have to enter the data manually and then run the function. I want to adjust the byte values using the LCD as an interface with a couple of button switches. Any suggestions gratefully received ;D

void setDateTime(){
  
  byte second=  1; //0-59
  byte minute=  00; //0-59
  byte hour=    17; //0-23
  byte day= 7;  //1-7, Sunday-Saturday.
  byte date= 5;  //1-31
  byte month = 12 ;  //  1-12
  byte year=    14;  //0-99
  
  Wire.beginTransmission(DS1307_ADDRESS);
  Wire.write(zero);  //Stop oscillator.
  Wire.write(decToBcd(second));
  Wire.write(decToBcd(minute));
  Wire.write(decToBcd(hour));
  Wire.write(decToBcd(day));
  Wire.write(decToBcd(date));
  Wire.write(decToBcd(month));
  Wire.write(decToBcd(year));
  
  Wire.endTransmission();
}
  
 byte decToBcd(byte val){  //Convert decimal to binary encoded decimal.
  return ( (val/10*16)+(val%10) );
 }
  
 byte bcdToDec(byte val){  //Convert binary encoded decimal to decimal.
  return ( (val/16*10)+(val%16) );
 }