DS3231 Real Time Clock (RTC) with Arduino and LowPower library

Dear Github-Fellows,

I’ve read quite some DS3231 threads here and elsewhere to get my project working but I haven’t managed it so far. Could you please help me?
I would like to do the following: Put my Arduino to deepsleep and measure every 1minute and every hour an analog value ( I am also interested in measuring like every 5 minutes but that’s a bit more difficult I guess).

Here is my Code:
I am using the Makuna library for the RTC: https://github.com/Makuna/Rtc
And the LowPower library from RocketScream: https://github.com/rocketscream/Low-Power

#include <Wire.h>
#include <RtcDS3231.h> //https://github.com/Makuna/Rtc
#include<LowPower.h>
int val;
int tempPin = A0;
const byte interruptPin = 2;
volatile bool alarm = 0;

RtcDS3231<TwoWire> rtcObject(Wire);

void setup() {

  Serial.begin(115200);

  pinMode(interruptPin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(interruptPin), handleInterrupt, FALLING);

  rtcObject.Begin();

  RtcDateTime timestamp = RtcDateTime( __DATE__ , __TIME__ );
  rtcObject.SetDateTime(timestamp);

  rtcObject.Enable32kHzPin(false);
  rtcObject.SetSquareWavePin(DS3231SquareWavePin_ModeAlarmOne);

  DS3231AlarmOne alarm1(
    0,
    0,
    0,
    1,
    DS3231AlarmOneControl_SecondsMatch);

  rtcObject.SetAlarmOne(alarm1);
  rtcObject.LatchAlarmsTriggeredFlags();
}

void loop() {
  LowPower.powerDown(SLEEP_FOREVER, ADC_OFF, BOD_OFF);
  if (alarm == true) {
    handleAlarm();
  }

}

void handleAlarm() {
  alarm = false;
  val = analogRead(tempPin);
  float mv = ( val/1024.0)*5000;
  float cel = mv/10;
  float farh = (cel*9)/5 + 32;
  Serial.print("TEMPRATURE = ");
  Serial.print(cel);
  Serial.print("*C");
  Serial.println();
  delay(1000);
  RtcDateTime timestamp = rtcObject.GetDateTime();

  Serial.print("time interrupt at: ");
  char time[10];

  sprintf(time, "%d:%d:%d",
          timestamp.Hour(),
          timestamp.Minute(),
          timestamp.Second()
         );
Serial.println(time);

  rtcObject.LatchAlarmsTriggeredFlags();

}

void handleInterrupt() {
  alarm = true;
}

Best,

Marco