Not able to open file in SD Card?

This is the code i'm currently using for a thermometer, and I can't seem to tell if the file was created or not.
DISCLAIMER: I know that the Time code isn't correct, pls no hate;

#include <Time.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>

**
 * Code is public (c)
 */

int tmp102Address = 0x48;
const int chipSelect = 4;
File myFile;
void setup(){
 Serial.begin(9600); //Set our baud rate to 9600 for our serial connection
 Wire.begin(); // Initiate the Wire library and join the I2C bus
 setTime(11,3,0,2,6,15);

 Serial.println("Initializing SD Card....");
 pinMode(10,OUTPUT);
while(!Serial){
  //waiting for serial
  Serial.println("##########################################");
  Serial.println("Waiting for Serial Connection...");
  Serial.println("##########################################");
}
Serial.println("##########################################");
Serial.println("Connecting to SD Card...");
Serial.println("##########################################");
if(!SD.begin(chipSelect)){
  Serial.println("==========================================");
  Serial.println("ERROR: Card not present or connection fail");
  Serial.println("==========================================");
  
  return;
}
Serial.println("##########################################");
Serial.println("SD Card has been fully connected to Arduino.");
Serial.println("##########################################");

/**
 * SD File Creation
 */


if(SD.exists("thermofile.txt")){
  Serial.println("############################");
  Serial.println("Data file exists");
  Serial.println("############################");
  
}
else {
  Serial.println("=========================");
  Serial.println("Data file does not exists");
  Serial.println("=========================");
  Serial.println("######################");
Serial.println("Creating thermofile...");
Serial.println("######################");
myFile = SD.open("thermofile.txt" FILE_WRITE);
myFile.close();
}



}

void digitalClockDisplay(){
  Serial.print(hour());
  printDigits(minute());
  printDigits(second());
  Serial.print(" ");
  Serial.print(day());
  Serial.print(" ");
  Serial.print(month());
  Serial.print(" ");
  Serial.print(year());
  Serial.println();
}

void loop(){
 String dataString = "";

 for(int analogPin = 0; analogPin < 3; analogPin++){
  int sens = analogRead(analogPin);
  dataString += String(sens);
  if(analogPin < 2){
    dataString += ",";
  }
 }
 File themofile = SD.open("thermofile.txt",FILE_WRITE);

  //Check dat
  if(themofile){
    Serial.println("###############");
    Serial.println("Opening ThemoFile");
    Serial.println("###############");
    themofile.println(dataString);
    themofile.close();
    //Closing Connection to the data.
    //Printing the data to serial console.
    Serial.println(dataString);
  }
  else {
    Serial.println("========================");
    Serial.println("ERROR: Exception while opening themofile.txt");
    Serial.println("========================");
    
  }
  

  float celsius = getTemperature(); // Get the temperature in C and save it as a float called celsius.
 
 Serial.print("Celsius: "); // Print our description of the temp
 Serial.println(celsius); // Print our temp in C

 
 
 
 float fahrenheit = (1.8 * celsius) + 32;  // Get the temperature in C and save it as a float called fahrenheit after converting it from celsius.
 Serial.print("Fahrenheit: "); // Print our description of the temp.
 Serial.println(fahrenheit); // Print the temp in F
 getDigitalClockDisplay();
Serial.println("=======================");

 Serial.write(13);
 delay(30000);
 
 
 
}
 
// Let’s take a look at our getTempurature function. Without it, nothing would work.
float getTemperature(){
 Wire.requestFrom(tmp102Address,2); // We use our wire library’s get two readings from our TMP102. We pass it the address and the quantity.
 
 
// You may have noticed that we didn’t do anything with the request. That’s because we have to read back we requested. We do that sequentially.
 byte MSB = Wire.read(); // The first byte we get, the Most Significant, get’s stored in MSB.
 byte LSB = Wire.read(); // The second byte we get, the Least Significant, get’s stored in LSB.
 
 
 int TemperatureSum = ((MSB << 8) | LSB) >> 4;
 
 float celsius = TemperatureSum*0.0625; // Convert our temp to celsius.
 return celsius; // Return our result to be printed.
}

void getDigitalClockDisplay(){
  // digital clock
  Serial.print(hour());
  printDigits(minute());
  printDigits(second());
  Serial.print(" ");
  Serial.print(day());
  Serial.print(" ");
  Serial.print(year());
  Serial.println();
}


void printDigits(int digits){
  Serial.print(":");
  if(digits < 10)
  Serial.print('0');
  Serial.print(digits);
}

DolphinDev:

String FILE_NAME = "thermofile.txt";

OMG! You are programming for a FAT filesystem!

jurs:
OMG! You are programming for a FAT filesystem!

8.3 filename - Wikipedia

Accidentely Uploaded wrong code, updated

DolphinDev:
Accidentely Uploaded wrong code, updated

Despite of your code update:
The 8.3 limit of FAT filenames has not changed since you posted the initial version of your code.

In fact, the 8.3 limit for FAT filenames had not changed since that filesystem had ben invented 50 years ago.

bump