const int lightDelay = 90000;
const byte movePin = 3;
const byte relayPin = 4;
long lastmoveMillis = 0;

void setup() {
    pinMode(movePin, INPUT);
    pinMode(relayPin, OUTPUT);
    digitalWrite(relayPin, HIGH);
}

void loop(){
  if (digitalRead(movePin) == 1) lastmoveMillis = millis();
  delay(100);
  if (lastmoveMillis > 0) activateRelay();
}

void activateRelay() {
  if ((millis() - lastmoveMillis) < lightDelay) digitalWrite(relayPin, LOW);
  if ((millis() - lastmoveMillis) > lightDelay) {
    digitalWrite(relayPin, HIGH);
    lastmoveMillis = 0;
  }
}