Clock - if statement doesent work

Okax so I started learniny Python for a week and i wanted to write a code that displays a clock. So this is it. Everything is fine but it wont switch from 24 to 0 / 12 to 0 and i don't get why. Do you have any tipps for a better style? [time.localtime] i've found too late :D [im not finished yet] (sorry for not pleasing you with my english)

from time import sleep


def wrong_input():
    global formt
    formt = input("Do you want to use the 24-Hours format?\nFor yes type Y, for no type N\n")
    if not (formt == "N" or formt == "n" or formt == "Y" or formt == "y"):
        print("ERROR, wrong input")
        wrong_input()


wrong_input()


def too_high():
    global hr
    hr = int(input("Please enter the Hours:\n"))
    if (formt == "N" or formt == "n") and hr > 12:
        print("ERROR")
        too_high()


too_high()
min = int(input("Please enter the Minutes:\n"))
sec = int(input("Please enter the Secondes:\n"))
while True:
    print(hr, ":", min, ":", sec)
    sec += 1
    sleep(1)
    if (sec >= 60):
        min += 1
        sec = 0
    if (min >= 60):
        hr += 1
        min = 0
    if (12 <= hr and formt == "N"):
        hr = 1
    if (23 <= hr and formt == "Y"):
        hr = 0