The display is 6,9 inch big (150x90 mm) and it's designed to hang it on the wall.
If you print four big and one small piece as I did you can use it as an watch.

If you want to put two displays together you have to glue them together.

ELECTRONICS:

1x Arduino NANO

1x Real Time Clock RTC DS3231 

1x Active Buzzer

86x 5mm LED's (color of your choice)

Installation:

1. You have to print out your variation of displays.
2. Push the LED's in the holes of the case
3. Put the cover on the case
4. Wire the LED's ground from each segment to a different digital output of the Arduino
5. Wire all the same pieces of the number to the same digital output (e.g. the top LED's of the first segment to the top LED's of the second segment and so on…)
6. Upload the code to the Arduino and you'r good to go :)

You can download the code in “Files” or copy it down below:

#include "SevSeg.h"
#include "RTClib.h"
SevSeg sevseg; //Instantiate a seven segment controller object
RTC_DS1307 rtc;
bool pnkt = false;
unsigned long secprev = 0;
unsigned long minprev = 0;
unsigned int pausen[12] = {475,525,580,635,700,755,805,855,905,965,1015,1065};
bool count = true;
int count2 = 100;
int bispause;
int BPS = 150;
void setup() {
Serial.begin(57600);
while (!Serial);
if (! rtc.begin()) {
Serial.println("Couldn't find RTC");
Serial.flush();
while (1) delay(10);
}
byte numDigits = 4;
byte digitPins[] = {5, 4, 3, 2};
byte segmentPins[] = {6, 7, 8, 9, 10, 11, 12};
bool resistorsOnSegments = true; // 'false' means resistors are on digit pins
byte hardwareConfig = N_TRANSISTORS; // See README.md for options
bool updateWithDelays = false; // Default 'false' is Recommended
bool leadingZeros = false; // Use 'true' if you'd like to keep the leading zeros
bool disableDecPoint = true; // Use 'true' if your decimal point doesn't exist or isn't connected
pinMode(13, OUTPUT);
//rtc.adjust(DateTime(2014, 1, 21, 3, 0, 0));     //RTC time adjust (Y, M, D, H, M, S)
sevseg.begin(hardwareConfig, numDigits, digitPins, segmentPins, resistorsOnSegments,
updateWithDelays, leadingZeros, disableDecPoint);
sevseg.setBrightness(100);
amogus();
amogus();
amogus();
}
void loop() {
DateTime time = rtc.now();
if(time.second() != secprev) {   //every second
count2++;
secprev = time.second();
if(count2 >= 20 && count2 < 30 && bispause < 100){
  digitalWrite(13, LOW);
  sevseg.setNumber(bispause);
}
else{
  pnkt = !pnkt;
  if(pnkt){
    digitalWrite(13, HIGH);
  }
  else{
    digitalWrite(13, LOW);
  }
  sevseg.setNumber(time.hour()*100+time.minute());
}

}
if(time.minute() != minprev){
minprev = time.minute();
bispause = 100;
for(int i = 0; i < sizeof(pausen); i++){
if(pausen[i] - time.hour()*60 - time.minute() > 0 && pausen[i] - time.hour()*60 - time.minute() < bispause){

bispause = pausen[i] - time.hour()*60 - time.minute();
}
if(pausen[i] == time.hour()*60 + time.minute()){
amogus();

}
}
count2 = 0;

}
sevseg.refreshDisplay(); // Must run repeatedly
}
void amogus(){
for(int i=6; i<=12; i++){
digitalWrite(i, HIGH);
}
digitalWrite(9, LOW);
digitalWrite(2, LOW);
digitalWrite(3, LOW);
digitalWrite(4, LOW);
digitalWrite(5, LOW);
tone(13, 523);     //C5
digitalWrite(2, HIGH);
delay(BPS);
noTone(13);
delay(BPS);
tone(13, 622);     //Eb5
digitalWrite(3, HIGH);
digitalWrite(2, LOW);
delay(BPS);
noTone(13);
delay(BPS);
tone(13, 698);     //F5
digitalWrite(4, HIGH);
digitalWrite(3, LOW);
delay(BPS);
noTone(13);
delay(BPS);
tone(13, 740);     //Gb5
digitalWrite(5, HIGH);
digitalWrite(4, LOW);
delay(BPS);
noTone(13);
delay(BPS);
tone(13, 698);     //F5
digitalWrite(4, HIGH);
digitalWrite(5, LOW);
delay(BPS);
noTone(13);
delay(BPS);
tone(13, 622);     //Eb5
digitalWrite(3, HIGH);
digitalWrite(4, LOW);
delay(BPS);
noTone(13);
delay(BPS);
tone(13, 523);     //C5
digitalWrite(2, HIGH);
digitalWrite(3, LOW);
delay(3BPS);
noTone(13);
delay(3BPS);
tone(13, 466);     //B4
digitalWrite(3, HIGH);
digitalWrite(2, LOW);
delay(BPS/2);
noTone(13);
delay(BPS/2);
tone(13, 587);     //D5
digitalWrite(4, HIGH);
digitalWrite(3, LOW);
delay(BPS/2);
noTone(13);
delay(BPS/2);
tone(13, 523);     //C5
digitalWrite(5, HIGH);
digitalWrite(4, LOW);
delay(3BPS);
noTone(13);
delay(2BPS);
noTone(13);
tone(13, 98);      //G3
digitalWrite(4, HIGH);
digitalWrite(5, LOW);
delay(BPS);
noTone(13);
delay(BPS);
tone(13, 131);     //C3
digitalWrite(2, HIGH);
digitalWrite(3, HIGH);
digitalWrite(4, HIGH);
digitalWrite(5, HIGH);

delay(2*BPS);
noTone(13);
delay(500);
}