Digital Clock

1) Project Overview

We will build a simple digital clock that shows the current date and time and updates every second. It will run in the terminal (the black/white text window). You will see the time change just like a real digital clock.

2) Learning Objectives

By the end of this project, you will:

Use Python's time module to get the current date and time.
Format time into a friendly string like HH:MM:SS.
Use a while loop to repeat actions every second.
Pause a program with time.sleep().
Print neatly on one line using carriage return (\r) and flush.
Handle stopping the program safely with Ctrl+C.

3) Step-by-Step Explanation

Create a new file:
- Open your code editor and create a file named digital_clock.py.
Import the time module:
- We will use time.strftime() to format the time and time.sleep() to wait 1 second between updates.
Decide the display:
- We'll show the date (like Mon, 14 Oct 2025) and the time (like 19:05:21) on one line.
Make an infinite loop:
- A while True loop lets the clock update forever (until you stop it).
Format the current time:
- Use time.strftime("%H:%M:%S") for 24-hour time (e.g., 19:05:21).
- Optional: use "%I:%M:%S %p" for 12-hour time (e.g., 07:05:21 PM).
- For the date, use something like "%a, %d %b %Y" (e.g., Mon, 14 Oct 2025).
Print on one line:
- Use print("\r" + line, end="", flush=True) so the time updates on the same line.
- Note: In some editors like IDLE, this may still print on new lines. That's okay. Try running the file in your system terminal for the "one-line" effect.
Pause for one second:
- Use time.sleep(1) so the time updates once per second.
Allow a clean exit:
- Wrap the loop in try/except and catch KeyboardInterrupt so pressing Ctrl+C stops the clock nicely.
Run your program:
- Open a terminal/command prompt, go to the folder with your file, and run: python digital_clock.py

4) Complete and Well-Commented Python Code

Try it Yourself »

# digital_clock.py
# A simple digital clock that updates every second in the terminal.

import time  # Built-in module for working with time and dates


def main():
    print("Digital Clock - Press Ctrl+C to stop")
    try:
        while True:
            # Format the current date and time.
            # Example date: Mon, 14 Oct 2025
            date_part = time.strftime("%a, %d %b %Y")

            # Example time (24-hour): 19:05:21
            # For 12-hour time with AM/PM, you could use: "%I:%M:%S %p"
            time_part = time.strftime("%H:%M:%S")

            # Build the display line
            line = f"{date_part}   {time_part}"

            # Print on the same line:
            # \r moves the cursor to the start of the line.
            # end="" avoids adding a new line each time.
            # flush=True forces the text to show immediately.
            print("\r" + line, end="", flush=True)

            # Wait 1 second before updating again
            time.sleep(1)

    except KeyboardInterrupt:
        # If the user presses Ctrl+C, exit nicely.
        print("\nClock stopped. Goodbye!")


# Run the program only if this file is executed directly
if __name__ == "__main__":
    main()

5) Output Examples

When you run the program, you'll see something like:

Digital Clock - Press Ctrl+C to stop
Mon, 14 Oct 2025 19:05:21
Mon, 14 Oct 2025 19:05:22
Mon, 14 Oct 2025 19:05:23
... (updates every second)

If you run it in a system terminal, you may see the time update on a single line, like this:

Digital Clock - Press Ctrl+C to stop
Mon, 14 Oct 2025 19:05:23 [and the seconds keep changing in place]

Press Ctrl+C to stop:

Clock stopped. Goodbye!

6) Small Exercise (Try This!)

Add a friendly greeting based on the hour

Idea: Show "Good Morning", "Good Afternoon", or "Good Evening" before the time.

Hints:

Get the current hour as a number:
hour = int(time.strftime("%H"))
Use if/elif/else:
- 5 <= hour < 12: "Good Morning"
- 12 <= hour < 18: "Good Afternoon"
- else: "Good Evening"
Include the greeting in your line:
line = f"{greeting} | {date_part} {time_part}"

7) Summary

Great job! You built a working digital clock using just a few lines of Python. You learned how to loop forever, pause your program, format dates and times, and print smoothly. Small projects like this build strong foundations. Keep experimenting—tiny changes can lead to cool new features. You've got this!

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