// https://forum.arduino.cc/t/time-isnt-converted-correct-from-unix-time/1060600/3

#include <time.h>

int32_t modifyEpoch()
{
  uint32_t epoch = 0;
  time_t rawtime = epoch;
  struct tm ts = *localtime(&rawtime);
  char  buf[8]{""};
  int32_t offset = 0;
  strftime(buf, sizeof(buf), "%Y", &ts); // get year of 0
  Serial.println(buf);
  if (atoi(buf) == 2000 )
  {
    offset = -946684800; 
    Serial.println(F("force offset"));
  }
  else  if (atoi(buf) != 1970 )
  {
    Serial.print (F("adopt function to handle epoch Start ")); Serial.println(buf);
  }
  return offset;
}

int32_t epochOffset = 0;

void setup() {
  Serial.begin(115200);
  epochOffset = modifyEpoch();   // call once
  uint32_t epoch = 1669978215;   //Fri Dec 02 2022 10:50:15 GMT+0000
  epoch += epochOffset;
  char buf[80];
  time_t rawtime = epoch; // time(epoch);
  struct tm ts = *localtime(&rawtime);
  strftime(buf, sizeof(buf), "%a %Y-%m-%d %H:%M:%S %Z", &ts);
  Serial.println(buf);
}

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

}