Timers in Arduino

Projects General Guidance
1

How to generate 2 hours time delay in Arduino using timers??
I don't want to use delay function..

2

You can do it without using delay() by using millis() instead. have a variable start stores the value of millis() at the start of the delay, then check to see if the current value of millis() has increased by two hour's worth of milliseconds.

3

Indeed, use millis(), that's the easiest. You get something like this:

unsigned long startTime;

void setup() {
  startTime = millis();
}

void loop() {
  if (millis() - startTime > 2 * 60 * 60 * 1000) {
    startTime = millis();
    doTwoHourThing();
  }
}