Several questions about datalogging project

Hi,
for filedate/time google for something like this,I think it´s somewhere in the Fat16 Libs examples

/*
 * User provided date time callback function.
 * See Fat16::dateTimeCallback() for usage.
 */
void dateTime(uint16_t* date, uint16_t* time) {
  // User gets date and time from GPS or real-time
  // clock in real callback function
  
  // return date using FAT_DATE macro to format fields
  *date = FAT_DATE(year, month, day);
  
  // return time using FAT_TIME macro to format fields
  *time = FAT_TIME(hour, minute, second);
}

Just in case you have your arduino connected to a PC, you can set the date/time via serial. Of course not possible, if your arduino is not connectd.
Best, Robert