Need Help About Consecutive Count

Hi there,
I am new on Arduino and this is my first topic here.
It is very relaxing and joyful to play with arduino.

My question is,
I have an variable named "interval". I want to control it with my analog joystick. When I change x axis to +, the interval will increase by 10 seconds and vice versa.
The problem is,
When I start to push the analog joystick x axis, the interval changes like this: 0, 15, 30 then -25. Why doesn't it increase to 45, 60, 75 etc? Could you please help? Thanks.
Here is my code;

// include the library code:
#include <LiquidCrystal.h>
const int x_pin = 0;
int interval = 0; // default interval süresi

// lcd ekranın giriş pinleri
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  // put your setup code here, to run once:
pinMode(7, OUTPUT);
pinMode(8, OUTPUT);
pinMode(9, OUTPUT);
pinMode(6, OUTPUT);

  lcd.begin(16, 2);

lcd.clear(); // karşılama ekranı 3sn
lcd.setCursor(0, 0);
lcd.print("   ArduSlider   ");
lcd.setCursor(0, 1);
lcd.print("      V1.0      ");
delay(1000);
   
}

void loop() {
  // put your main code here, to run repeatedly:


lcd.clear(); // interval göstermeye basla
lcd.setCursor(0, 0);
lcd.print("Interval:"); // üst satır
lcd.setCursor(0, 1);
lcd.print(interval/1000); // alt satır interval süresi (sn)
lcd.setCursor(9, 1);
lcd.print("sn");

if (analogRead(x_pin) < 520)  {
  interval = interval - 10000; // her adımda x saniye düşür
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Interval:"); // üst satır
  lcd.setCursor(0, 1);
  lcd.print(interval/1000); // alt satır interval süresi (sn)
  lcd.setCursor(9, 1);
  lcd.print("sn");
  delay(50); // butona basılı tutunca sürekli azalma sıklığı buradan ayarlanıyor
  }
if (analogRead(x_pin) > 530) {
  interval = interval + 10000; // her adımda x saniye arttır
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Interval:"); // üst satır
  lcd.setCursor(0, 1);
  lcd.print(interval/1000); // alt satır interval süresi (sn)
  lcd.setCursor(9, 1);
  lcd.print("sn");
  delay(50); // butona basılı tutunca sürekli artma sıklığı buradan ayarlanıyor
  }
delay(250);

  
}

int interval = 0;Try long instead

AWOL:
int interval = 0;Try long instead

int long interval = 0LL worked. Thank you.

int long interval = 0LL worked.

Why are you storing a long long in a long? The correct suffix (and type) is UL, for unsigned long.

The int part is not necessary. No other type can have the long prefix.

You want to bookmark this page and then check the parts about data types.