Data from DS3231 displayed on 4 MAX7219

DS3231_MD_MAX72xx.ino

#include <MD_Parola.h>
#include <MD_MAX72xx.h>
#include <SPI.h>
#include <DS3231.h>

#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define MAX_DEVICES 16
#define NUM_ZONES 4

#define CLK_PIN   13
#define DATA_PIN  11
#define CS_PIN    10

MD_Parola P = MD_Parola(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);
DS3231 myRTC;

void setup() {
  Serial.begin(57600);
  P.begin(NUM_ZONES);
  P.setIntensity(3);

  // set the zone boundaries
  P.setZone(0, 0, 3);
  P.setZone(1, 4, 7);
  P.setZone(2, 8, 11);
  P.setZone(3, 12, 15);
}

char* getDow() {
    const char* weekdays[] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
    byte theWeekday = myRTC.getDoW();

    return weekdays[theWeekday];
}

char* getDate() {
    bool CenturyBit;
    byte date = myRTC.getDate();
    byte month = myRTC.getMonth(CenturyBit);

    static char dateString[20];
    sprintf(dateString, "%02d/%02d", date, month);
    return dateString;
}

char* getTime() {
    bool h12;
    bool hPM;

    byte hour = myRTC.getHour(h12, hPM);
    byte min = myRTC.getMinute();

    static char timeString[20];
    sprintf(timeString, "%02d:%02d", hour, min);

    return timeString;
}

char* getTemp() {
    float rtcTemp = myRTC.getTemperature();

    static char tempString[10]; // Enough space to hold the temperature as a string
    // Convert float to string
    dtostrf(rtcTemp, 2, 1, tempString); // 2 is minimum width, 1 is precision
    sprintf(tempString, "%sc", tempString);

    return tempString;
}

void loop() {
  char* time = getTime();
  char* temp = getTemp();
  char* date = getDate();
  char* dow = getDow();

  if (P.displayAnimate())
    P.displayZoneText(3, time, PA_LEFT, 0, 0, PA_NO_EFFECT, PA_NO_EFFECT);
    P.displayZoneText(2, dow, PA_LEFT, 0, 0, PA_NO_EFFECT, PA_NO_EFFECT);
    P.displayZoneText(1, date, PA_LEFT, 0, 0, PA_NO_EFFECT, PA_NO_EFFECT);
    P.displayZoneText(0, temp, PA_LEFT, 0, 0, PA_NO_EFFECT, PA_NO_EFFECT);

  delay(1000);
}