big_date.py

import tkinter as tk
from string import ascii_letters
from datetime import date

my_date = date.today()
my_date.strftime('%A')

def show_date():
    s = my_date.strftime('%a').upper()
    #s = 'Manual text here...'
    l.config(text=s, bg='black', fg='white')
    root.after(100, show_date)

root = tk.Tk()
root.wm_overrideredirect(True)
root.config(bg='black')
root.geometry("{0}x{1}+0+0".format(root.winfo_screenwidth(), root.winfo_screenheight()))
root.bind("<Escape>", lambda x: root.destroy())

l = tk.Label(text='', font=('Barlow Semi Condensed', 400, 'bold'))
l.pack(expand=True)

show_date()
root.mainloop()