7 Segment Clock

Thanks for posting this code, is there a way to edit it so it works as a countdown from 59.59 (mm.ss)

posably like this

#include "LedControl.h"     // Include the LedControl library
LedControl lc=LedControl(12,11,10,1); // Set up an LED object on pins 12,11,10

int seconds_ones;
int minutes_ones;
int seconds_tens;        // Initialise values for tens and ones units of m,s
int minutes_tens;        // these are the values actually sent to the LEDs
volatile unsigned char tick;
unsigned char seconds = 0;
unsigned char minutes = 60;     // Inititialise actual values for mm,ss

ISR (TIMER2_OVF_vect) {        // When timer2 overflows...
  tick++;                      // increment tick
  display_time ();             // send the time to the LEDs to be displayed
  
}


void display_time () {            // Function to display the time

    seconds_ones = seconds % 10;        // Get the 1's digit of seconds
    if (seconds>=10){             // If seconds greater than 10
     seconds_tens = seconds / 10;}      // Get 10's digit of seconds
    else {
   seconds_tens = 0;}          // Otherwise 10s is 0

    minutes_ones = minutes % 10;        // Repeat for minutes
    if (minutes>=10){
     minutes_tens = minutes / 10 ;}
    else {
   minutes_tens = 0;}


    lc.setDigit(0,0,(byte)seconds_ones,false);  // Send digits to LEDs
    lc.setDigit(0,1,(byte)seconds_tens,false);
    lc.setDigit(0,2,(byte)minutes_ones,false);
    lc.setDigit(0,3,(byte)minutes_tens,false);
}







void loop () {

if (tick) {                             // If a tick has occured
  seconds = seconds - 1;                // Increment the seconds
  tick = 0;                             // reset the tick flag
  if (seconds>59){                      // If a minute has passed
  seconds = 0;                          // Send seconds back to 0
  minutes = minutes - 1;                // Increment the minutes
    minutes = 0;                        // Send the minutes back to 0
   }
  }
 }
}
}