Here is my try I would appreciate if you could support me.

Here is my try I would appreciate if you could support me. i can not move to countDown() function in the loop if i press start I need help to figure out a good technique of declaring functions in void loop in arduino

Im trying to build this project with a simple code Object is to hit up button to increment minutes or down to decrement minutes then hit start to start countdown  , white its counting relay will turn On light till counting is done will turn light off and if i hit end button while counting it will end counting and turn off relay.

Here is my try i would appreciate if you could support me.

#include <LiquidCrystal.h>

LiquidCrystal lcd(1,2,4,5,6,7);

#define numberOfSeconds(num) ((num/1000) % 60 )
#define numberOfMinutes(num) (((num/1000) / 60) % 60)

//unsigned long timeLimit = 3600000; // 1000 ms in 1sec, 60secs in 1min, 60mins in 1hr. so , 1000x60x60 = 3600000ms = 1hr

const int upBtn = 8;
const int downBtn = 9;
const int startBtn = 10;
const int endBtn = 11;

int btnPushCounter = 0;
int minutes;
int seconds;
unsigned long minutesGiven;
unsigned long timeLimit;
unsigned long timeRemaining;

int upBtnState = 0;
int lastUpBtnState = 0;

int downBtnState = 0;
int lastDownBtnState = 0;

int startBtnState = 0;
int lastStartBtnState = 0;

int endBtnState = 0;
int lastEndBtnState = 0;

bool bPress = false;

void setup() {

 lcd.begin(16,2); 
 pinMode(upBtn, INPUT_PULLUP);
 pinMode(downBtn, INPUT_PULLUP);
 pinMode(startBtn, INPUT_PULLUP);
 pinMode(endBtn, INPUT_PULLUP);

 lcd.clear();
 lcd.setCursor(0,0);
 lcd.print("Minutes : ");
 lcd.print(btnPushCounter);
}
void loop() {
    
    checkUp();
    checkDown();
//    countDown();
    if(bPress){
      bPress = false;
      displayNumber();
    }
}

void displayNumber(){ 
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("Minutes : ");
    lcd.print(btnPushCounter);    
}

void checkUp(){
  upBtnState = digitalRead(upBtn);
  // compare the buttonState to its previous state
  if (upBtnState != lastUpBtnState) {
    // if the state has changed, increment the counter
    if (upBtnState == HIGH) {
        bPress = true;
      btnPushCounter++;
    }
    delay(50);
  }
  // save the current state as the last state, for next time through the loop
  lastUpBtnState = upBtnState;
}

void checkDown(){
  downBtnState = digitalRead(downBtn);

  // compare the buttonState to its previous state
  if (downBtnState != lastDownBtnState && btnPushCounter != 0 ) {
    // if the state has changed, increment the counter
    if (downBtnState == HIGH) {
        bPress = true;
      btnPushCounter--;
    } 
    // Delay a little bit to avoid bouncing
    delay(50);
  }
  // save the current state as the last state, for next time through the loop
  lastDownBtnState = downBtnState;
}

void checkStart(){
  startBtnState = digitalRead(startBtn);
  if(startBtnState != lastStartBtnState){
    if(startBtnState == HIGH){
      bPress = true;
//      lcd.
    }
  }
}

void countDown() {
//  unsigned long timeLimit = 3600000;
  minutesGiven = btnPushCounter;
  timeLimit = minutesGiven * 1000 * 60;
  timeRemaining = timeLimit - millis();
  while(timeRemaining > 0){
    seconds = numberOfSeconds(timeRemaining);
    minutes = numberOfMinutes(timeRemaining);
    lcd.setCursor(2,7);
    lcd.print(minutes);
    lcd.print(" ");
    lcd.print(seconds);
    delay(50);
    timeRemaining = timeLimit - millis();
  }
}

I'm trying to build this project with a simple code. Object is to hit up button to increment minutes or down to decrement minutes then hit start to start countdown, while its counting relay will turn On light till counting is done will turn light off and if I hit end button while counting it will end counting and turn off relay.

Here is my try I would appreciate if you could support me.

#include <LiquidCrystal.h>

LiquidCrystal lcd(1,2,4,5,6,7);

#define numberOfSeconds(num) ((num/1000) % 60 )
#define numberOfMinutes(num) (((num/1000) / 60) % 60)

//unsigned long timeLimit = 3600000; // 1000 ms in 1sec, 60secs in 1min, 60mins in 1hr. so , 1000x60x60 = 3600000ms = 1hr

const int upBtn = 8;
const int downBtn = 9;
const int startBtn = 10;
const int endBtn = 11;

int btnPushCounter = 0;
int minutes;
int seconds;
unsigned long minutesGiven;
unsigned long timeLimit;
unsigned long timeRemaining;

int upBtnState = 0;
int lastUpBtnState = 0;

int downBtnState = 0;
int lastDownBtnState = 0;

int startBtnState = 0;
int lastStartBtnState = 0;

int endBtnState = 0;
int lastEndBtnState = 0;

bool bPress = false;

void setup() {

 lcd.begin(16,2); 
 pinMode(upBtn, INPUT_PULLUP);
 pinMode(downBtn, INPUT_PULLUP);
 pinMode(startBtn, INPUT_PULLUP);
 pinMode(endBtn, INPUT_PULLUP);

 lcd.clear();
 lcd.setCursor(0,0);
 lcd.print("Minutes : ");
 lcd.print(btnPushCounter);
}
void loop() {
    
    checkUp();
    checkDown();
//    countDown();
    if(bPress){
      bPress = false;
      displayNumber();
    }
}

void displayNumber(){ 
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("Minutes : ");
    lcd.print(btnPushCounter);    
}

void checkUp(){
  upBtnState = digitalRead(upBtn);
  // compare the buttonState to its previous state
  if (upBtnState != lastUpBtnState) {
    // if the state has changed, increment the counter
    if (upBtnState == HIGH) {
        bPress = true;
      btnPushCounter++;
    }
    delay(50);
  }
  // save the current state as the last state, for next time through the loop
  lastUpBtnState = upBtnState;
}

void checkDown(){
  downBtnState = digitalRead(downBtn);

  // compare the buttonState to its previous state
  if (downBtnState != lastDownBtnState && btnPushCounter != 0 ) {
    // if the state has changed, increment the counter
    if (downBtnState == HIGH) {
        bPress = true;
      btnPushCounter--;
    } 
    // Delay a little bit to avoid bouncing
    delay(50);
  }
  // save the current state as the last state, for next time through the loop
  lastDownBtnState = downBtnState;
}

void checkStart(){
  startBtnState = digitalRead(startBtn);
  if(startBtnState != lastStartBtnState){
    if(startBtnState == HIGH){
      bPress = true;
//      lcd.
    }
  }
}

void countDown() {
//  unsigned long timeLimit = 3600000;
  minutesGiven = btnPushCounter;
  timeLimit = minutesGiven * 1000 * 60;
  timeRemaining = timeLimit - millis();
  while(timeRemaining > 0){
    seconds = numberOfSeconds(timeRemaining);
    minutes = numberOfMinutes(timeRemaining);
    lcd.setCursor(2,7);
    lcd.print(minutes);
    lcd.print(" ");
    lcd.print(seconds);
    delay(50);
    timeRemaining = timeLimit - millis();
  }
}