I’m working on this project building a Digital clock; so far I have a code for a single alarm.
I need more than one alarm; four alarms a day and one every three days.
I put together a DS12887 (RTC) with a DS89c450 (8951)
I have not idea how to program a microcontroller I took a class long time ago and I just learn assembly language, really light programs and Very general.
Please, I need help to update this code
Thank in advance.

//Program for Digital Clock using RTC DS12887 & 8051 microcontroller with alarm set function
/*24 hr clock
set p3^3=0,then start=0 them set time by dig_hr1 & dig_min1, then remove p3^3 & start	*/
#include<reg51.h>
#include<absacc.h>
#define dataport P2	// Dataport for LCD
#define port P1
#define alarm P3


sbit reset = port^0;
sbit rs = port^1;
sbit rw = port^2;
sbit e = port^3;
sbit dig_hr1=port^4;
sbit dig_min1=port^5;
sbit digalarm_hr1=alarm^4;
sbit digalarm_min1=alarm^5;
sbit alarmport=alarm^0;
sbit start=port^6;

int  min1=0,hr1=0,alarmmin1=0,alarmhr1=0;
int min0=60,hr0=25;
unsigned char sec0=60,min00,hr00,hr,min,sec,alarmmin,alarmhr;

void delay(unsigned int msec )
{
	int i ,j ;
	for(i=0;i<msec;i++)
	for(j=0; j<1275; j++);
}

unsigned char num(int d)
{
	switch(d)
	{
		case 0:{
				return 0x00;
				break;
				}
		case 1:{
				return 0x01;
				break;
				}
		case 2:{
				return 0x02;
				break;
				}
		case 3:{
				return 0x03;
				break;
				}
		case 4:{
				return 0x04;
				break;
				}
		case 5:{
				return 0x05;
				break;
				}
		case 6:{
				return 0x06;
				break;
				}
		case 7:{
				return 0x07;
				break;
				}
		case 8:{
				return 0x08;
				break;
				}
		case 9:{
				return 0x09;
				break;
				}
		case 10:{
				return 0x10;
				break;
				}
		case 11:{
				return 0x11;
				break;
				}
		case 12:{
				return 0x12;
				break;
				}
		case 13:{
				return 0x13;
				break;
				}
		case 14:{
				return 0x14;
				break;
				}
		case 15:{
				return 0x15;
				break;
				}
		case 16:{
				return 0x16;
				break;
				}
		case 17:{
				return 0x17;
				break;
				}
		case 18:{
				return 0x18;
				break;
				}
		case 19:{
				return 0x19;
				break;
				}
		case 20:{
				return 0x20;
				break;
				}
		case 21:{
				return 0x21;
				break;
				}
		case 22:{
				return 0x22;
				break;
				}
		case 23:{
				return 0x23;
				break;
				}
		case 24:{
				return 0x24;
				break;
				}
		case 25:{
				return 0x25;
				break;
				}
		case 26:{
				return 0x26;
				break;
				}
		case 27:{
				return 0x27;
				break;
				}
		case 28:{
				return 0x28;
				break;
				}
		 case 29:{
				return 0x29;
				break;
				}
		case 30:{
				return 0x30;
				break;
				}
		case 31:{
				return 0x31;
				break;
				}
		case 32:{
				return 0x32;
				break;
				}
		case 33:{
				return 0x33;
				break;
				}
		case 34:{
				return 0x34;
				break;
				}
		case 35:{
				return 0x35;
				break;
				}
		case 36:{
				return 0x36;
				break;
				}
		case 37:{
				return 0x37;
				break;
				}
		case 38:{
				return 0x38;
				break;
				}
		case 39:{
				return 0x39;
				break;
				}
		case 40:{
				return 0x40;
				break;
				}
		case 41:{
				return 0x41;
				break;
				}
		case 42:{
				return 0x42;
				break;
				}
		case 43:{
				return 0x43;
				break;
				}
		case 44:{
				return 0x44;
				break;
				}
		case 45:{
				return 0x45;
				break;
				}
		case 46:{
				return 0x46;
				break;
				}
		case 47:{
				return 0x47;
				break;
				}
		case 48:{
				return 0x48;
				break;
				}
		case 49:{
				return 0x49;
				break;
				}
		case 50:{
				return 0x50;
				break;
				}
		case 51:{
				return 0x51;
				break;
				}
		case 52:{
				return 0x52;
				break;
				}
		case 53:{
				return 0x53;
				break;
				}
		case 54:{
				return 0x54;
				break;
				}
		case 55:{
				return 0x55;
				break;
				}		 
		case 56:{
				return 0x56;
				break;
				}
		case 57:{
				return 0x57;
				break;
				}
		case 58:{
				return 0x58;
				break;
				}
		case 59:{
				return 0x59;
				break;
				}
	}
}

void lcd_cmd(unsigned char item)
{
	dataport = item;
	rs= 0;
	rw=0;
	e=1;
	delay(1);
	e=0;
	return;
}

// DATA SENDING FUNCTION
void lcd_data(unsigned char item)
{
	dataport = item;
	rs= 1;
	rw=0;
	e=1;
	delay(1);
	e=0;
	return;
}

void lcd_data_string(unsigned char *str)
{
	int i=0;
	while(str[i]!='')
	{
		lcd_data(str[i]);
		i++;
		delay(1);
	}
	return; 
}

void lcd_data_int(int time_val)
{
	int int_amt;
	int_amt=time_val/10;
	lcd_data(int_amt+48);
	int_amt=time_val%10;	 
	lcd_data(int_amt+48);
}

void lcd()			// Function to initialize LCD
{
	lcd_cmd(0x38);		  
	delay(5);
	lcd_cmd(0x0C);        
	delay(5);
	lcd_cmd(0x80);
	delay(5);
}

void set_rtc_time( int q)  
{
	XBYTE[10]=0x20;
	XBYTE[11]=0x82;
	XBYTE[0]=0x00;
	if(q==1)
	{
		XBYTE[2]=min;
		XBYTE[4]=hr;
	}
	XBYTE[7]=0x01;
	XBYTE[8]=0x01;
	XBYTE[9]=0x10;
	XBYTE[1]=0xff;
	if(q==2)
	{
		XBYTE[3]=alarmmin;
		XBYTE[5]=alarmhr;
	}
	XBYTE[11]=0x22;
}

//function to set hours
void set_hr1(char a,int b)
{
	if(b==1)
	{
		hr1++;
		if(hr1>23)
		hr1=0;
		lcd_cmd(a);
		lcd_data_int(hr1);
		lcd_data(':');
	}
	else
	{
		alarmhr1++;
		if(alarmhr1>23)
		alarmhr1=0;
		lcd_cmd(a);
		lcd_data_int(alarmhr1);
		lcd_data(':');
	}
}

//function to set minute
void set_min1(char a,int b)
{
	if(b==1)
	{
		min1++;
		if(min1>59)
		min1=0;
		lcd_cmd(a);
		lcd_data_int(min1);
	}
	else
	{
		alarmmin1++;
		if(alarmmin1>59)
		alarmmin1=0;
		lcd_cmd(a);
		lcd_data_int(alarmmin1);
	}
}

void set_time()	interrupt 0
{
	reset=0;
	lcd_cmd(0x01);
	if(start==0)
	{
		lcd_data_string("SET TIME");
		lcd_cmd(0x8A);
		lcd_data_int(hr1);
		lcd_data(':');
		lcd_data_int(min1);
		lcd_cmd(0xc0);
		while(start==0)
		{
			delay(10);
			if(dig_hr1==0)
			set_hr1(0X8a,1);
			if(dig_min1==0)
			set_min1(0X8d,1);	 
		}
	}
	lcd_cmd(0x01);
	hr=num(hr1);
	min=num(min1);
	set_rtc_time(1);
	lcd_cmd(0x01);
	lcd_cmd(0x80);
	lcd_data_string("TIME:");
	hr0=25;
	min0=60;
}

void set_alarm()	interrupt 2					 // Time set function
{
	reset=0;
	lcd_cmd(0x01);
	if(start==0)
	{
		lcd_data_string("SET ALARM");
		lcd_cmd(0x8b);
		lcd_data_int(alarmhr1);
		lcd_data(':');
		lcd_data_int(alarmmin1);
		while(start==0)
		{
			delay(10);
			if(digalarm_hr1==0)
			set_hr1(0X8b,2);
			if(digalarm_min1==0)
			set_min1(0X8e,2);	 
		}
	}
	lcd_cmd(0x01);
	alarmhr=num(alarmhr1);
	alarmmin=num(alarmmin1);
	set_rtc_time(2);
	lcd_cmd(0x01);
	lcd_cmd(0x80);
	lcd_data_string("TIME:");
	hr0=25;
	min0=60;
}

void bcdconv(unsigned char mybyte)
{
	unsigned char x,y;
	x=	mybyte & 0x0F;
	x=x | 0x30;
	y= mybyte & 0xF0;
	y=y>>4;
	y=y | 0x30;
	lcd_data(y);
	lcd_data(x);
}

void alarm1() 							  // Function to check alarm 
{
	reset=0;
	reset=1;
	lcd_cmd(0xc3);
	lcd_data_string("alarm");
	delay(100);
	lcd_cmd(0xc3);
	lcd_data_string("     ");
}

void read_rtc_display() 		 //Function to read RTC
{ 
	hr00=num(hr0);
	min00=num(min0);
	XBYTE[11]=0x22;
	hr=XBYTE[4];
	lcd_cmd(0x87);
	min=XBYTE[2];
	sec=XBYTE[0];
	if(hr!=hr00)
	{
		lcd_cmd(0X87);
		bcdconv(hr);
		lcd_data(':');
		hr0=hr;
	}
	if(min!=min00)
	{
		lcd_cmd(0X8A);
		bcdconv(min);
		lcd_data(':');
		min0=min;
	}
	if(sec!=sec0)
	{
		lcd_cmd(0x8D);
		bcdconv(sec);
		sec0=sec;
	}
}

void main()
{
	reset=1;
	lcd();
	XBYTE[10]=0x20;
	lcd_cmd(0x01);
	IE=0x85;
	lcd_cmd(0x80);
	lcd_data_string("TIME:");
	while(1)
	{
		read_rtc_display();
		if(alarmhr ==hr && alarmmin ==min )
		{
			alarm1();
		}
	}
}