DS1302 digital tube display time and date adjustable C language programming

#include <DS1302.h>
//define common anode font code 0123456789-
unsigned char code dispcode[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0xbf};
unsigned char time[]={0,0,0,0,0,0,0,0};//used to store time
unsigned char date[]={0,0,0,0,0,0,0,0};//used to store date
SYSTEMTIME time1; //A structure named SYSTEMTIME has been defined in the ds1302.h file. Here we define a variable named
                     //time in the SYSTEMTIME structure        
void delay(unsigned char i) //delay subroutine  
{
  unsigned char j;
  while((i--)!=0)
  {
    for(j=123;j>0;j--);
  }
}
unsigned char button_time(n,x,y) //Clock adjustment subroutine
unsigned char n,x,y;
{
    if(P1_7==0)
    {
        delay(50);
        if(P1_7==0)
     {
         n++;
            if(n==x)
         n=0;
            while(P1_7==0);
     }
    }

    if(P1_5==0)
    {
        delay(50);
        if(P1_5==0)
     {
            if(n==0)
         n=y;
         else
            n--;      
            while(P1_5==0);
        }
    }
    return n;
}

unsigned char button_date(n,x,y) //Date adjustment subroutine
unsigned char n,x,y;
{
    if(P1_7==0)
    {
        delay(50);
        if(P1_7==0)
     {
         n++;
            if(n==x)
         n=1;
            while(P1_7==0);
     }
    }

    if(P1_5==0)
    {
        delay(50);
        if(P1_5==0)
     {
            if(n==1)
         n=y;
         else
            n--;      
            while(P1_5==0);
        }
    }
    return n;
}

void display(second10,second1,minute10,minute1,hour10,hour1) //display subroutine
unsigned char second10,second1,minute10,minute1,hour10,hour1;  
{
  P2=0xfe;
  P0=dispcode[second10]; //display the tens digit of seconds
  delay(1);

  P2=0xfd;
  P0=dispcode[second1]; //Display the units digit of seconds
  delay(1);

  P2=0xfb;
  P0=dispcode[10]; //display "-"
  delay(1);

  P2=0xf7;
  P0=dispcode[minute10]; //display the tens digit of minute
  delay(1);

  P2=0xef;
  P0=dispcode[minute1]; //display the unit digit of minute
  delay(1);

  P2=0xdf;
  P0=dispcode[10]; //display "-"
  delay(1);

  P2=0xbf; P0=dispcode[hour10]; //   delay(1)
  for the displayed tens digit ;

  P2=0x7f;
  P0=dispcode[hour1]; //the unit digit of the display
  delay(1);
} 

void main()
{  
   unsigned char flag;
   Initial_DS1302(); //Initialize the DS1302 clock chip,   
   while(1)           
   {
       DS1302_GetTime(&time1); //Read time parameters            
       time[5]=(time1.Second)%10; //Store the units digit of the second into time[5]
       time[4]=(time1.Second)/10; //Store the tens digit of the second into time[4]
       time[3]=(time1.Minute)%10; //Store the units digit of the minute into time[3]
       time[2]=(time1.Minute)/10; //Store the tens digit of the minute into time[2]
       time[1]=(time1.Hour)%10; //Store the units digit of the hour into time[1]
       time[0]=(time1.Hour)/10; //Store the tens digit of the hour into time[0]
    date[5]=(time1.Day)%10;
    date[4]=(time1.Day)/10;
    date[3]=(time1.Month)%10;
    date[2]=(time1.Month)/10;
    date[1]=(time1.Year)%10;
    date[0]=(time1.Year)/10;  

    if(P1_4==0) //If you press the Time Start key once, the clock starts to display the time normally, and press it again to display the date
    {
   delay(50);
   if(P1_4==0)
   {
    flag++;
    if(flag>1)
    {
     flag=0;
    }
   }
   while(P1_4==0);
  }
    if(P1_6==0) //If you press the Time Set key once, the date starts to be displayed, and press it again to enter the date and clock adjustment mode
    {
      delay(50);
   if(P1_6==0)
   {
    flag++;
    if(flag>7)
    {
     flag=0;
    }
   }
   while(P1_6==0);
  }

  switch(flag)
  {
   case 0:display(time[0],time[1],time[2],time[3],time[4],time[5]); //Call the sub-function display to display the data stored in the array time
       break;

   case 1:display(date[0],date[1],date[2],date[3],date[4],date[5]); //Call the sub-function display to display the data stored in the array date
       break;

   case 2:time1.Year=button_date(time1.Year,100,99);      //调整年
       DS1302_SetTime(0x8c,time1.Year);
       display(date[0],date[1],10,10,10,10);
       break;

   case 3:time1.Month=button_date(time1.Month,13,12);      //调整月
       DS1302_SetTime(0x88,time1.Month);
       display(10,10,date[2],date[3],10,10);
       break;

   case 4:time1.Day=button_date(time1.Day,32,31);       //调整日
       DS1302_SetTime(0x86,time1.Day);
       display(10,10,10,10,date[4],date[5]);
       break;

   case 5:time1.Hour=button_time(time1.Hour,24,23);         //调整时
       DS1302_SetTime(0x84,time1.Hour);
       display(time[0],time[1],10,10,10,10);
       break;

   case 6:time1.Minute=button_time(time1.Minute,60,59);        //调整分
       DS1302_SetTime(0x82,time1.Minute);
       display(10,10,time[2],time[3],10,10);
       break;

   case 7:time1.Second=button_time(time1.Second,60,59);        //调整秒
          DS1302_SetTime(0x80,time1.Second);
       display(10,10,10,10,time[4],time[5]);
       break;
  }   
 }
}