compte a rebours lcd

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd1(0x26,20,4);

const int BP = 7;
int BPstate = 0;

int time;
int heure;
int minute;
int seconde;

long milliref;

void setup(){

    pinMode(BP, INPUT);
    lcd1.init();
    lcd1.backlight();

    heure = 0;
    minute = 1;
    seconde = 0;
    time = (seconde + (60 * minute) + (3600 * heure));
}
void loop()    {

    BPstate = digitalRead(BP);
    lcd1.setCursor(1, 0);
    lcd1.print("                ");

    lcd1.setCursor(3, 0);
    lcd1.print("En Attente");
    delay(10);
    lcd1.setCursor(0, 1);
    lcd1.print("                ");

if (BPstate == HIGH) {
        milliref = millis();
        while (time > 1) {
            if (millis() > (milliref + 1000)) {
                seconde = seconde - 1;
                time = time - 1;
                milliref = milliref + 1000;
            }
            if (minute > 0) {
                if (seconde < 0) {
                    minute--;
                    seconde = 59;
                }
            }
            if (heure > 0) {
                if (minute <= 0) {
                    if (time == 3600 * heure - 1) {
                        heure--;
                        minute = 59;
                        seconde = 59;
                    }
                }
            }
            Display();
            delay(980);
        }
    }
}
void Display() {

    lcd1.setCursor(1, 0);
    lcd1.print("Temps Restant:");
    lcd1.setCursor(1, 0);
    lcd1.setCursor(4, 1);
    lcd1.print("00:00:00");

    if (heure >= 10) {
        lcd1.setCursor(4, 1);
    }
    else{
        lcd1.setCursor(5, 1);
    }
        lcd1.print(heure);

    if (minute >= 10){
            lcd1.setCursor(7, 1);
    }
    else {
        lcd1.setCursor(8, 1);
    }
    lcd1.print(minute);

    if (seconde >= 10){
        lcd1.setCursor(10, 1);
    }
    else {
        lcd1.setCursor(11, 1);
    }
    lcd1.print(seconde);

    if (time <= 0){
    }
    }