Это пример того, что вы ищете:
import tkinter as tk
from tkinter import ttk
import time
# change every four hours
ranges = {'00': '1', '01': '1', '02': '1', '03': '1',
'04': '2', '05': '2', '06': '2', '07': '2',
'08': '3', '09': '3', '10': '3', '11': '3',
'12': '4', '13': '4', '14': '4', '15': '4',
'16': '5', '17': '5', '18': '5', '19': '5',
'20': '6', '21': '6', '22': '6', '23': '6', }
def update_label():
"""use current hour as an index to my ranges dict and update label"""
print('updating!')
label_var.set(ranges[time.strftime('%H')])
win.after(1000, update_label)
# create my window
win = tk.Tk()
# create string var for my label and init to 1
label_var = tk.StringVar(value=1)
# create label
myLabel = ttk.Label(win, textvariable=label_var)
# add label to window
myLabel.grid(column=0, row=0, sticky='WE')
# call update after 1000 ms
win.after(1000, update_label)
win.mainloop() # run app