Setting the time on an arduino mega using Adafruit FONA

i know the Mega has no realtime clock and i was wondering my project had a GSM card (Adafruit FONA)
and it has an option to get the time from the GSM network

boolean Adafruit_FONA::readRTC(uint8_t *year, uint8_t *month, uint8_t *date, uint8_t *hr, uint8_t *min, uint8_t *sec) {
  uint16_t v;
  sendParseReply(F("AT+CCLK?"), F("+CCLK: "), &v, '/', 0);
  *year = v;

  Serial.println(*year);
}

boolean Adafruit_FONA::enableRTC(uint8_t i) {
  if (! sendCheckReply(F("AT+CLTS="), i, F("OK"))) 
    return false;
  return sendCheckReply(F("AT&W"), F("OK"));
}

is there any way to set this as a system time on bootup ? and use it system wide for timestamps

ie i have the option to press an RF button i would like a log of when it was pressed and the log be written to a SD card in a txt file
i would also like the file to have a timestamp when it was last appended to

now all this is getting over my head now and i was wondering if anyone could point me in the right direction how to accomplish this

Thanks in advance

The Time library has the ability to keep track of time. It can be set/synced using almost any source of time/date information.

thanks i will look in to this