I am trying to execute an alarm function in tkinter but it is not working properly

I am trying to Execute the function in tkinter as I want function to run in background I have done following code. Also I am trying to execute it inside a while loop but its not looping through.

t1 = dt.time(hour = 13, minute= 24)
t2 = dt.time(hour= 13, minute= 4)
timetable = [t1, t2]
root = Tk() 

def Alarm():
      current_time = now_time.strftime("%H:%M:%S")
      print(current_time)
      print(timetable[0])
      while True:
            if timetable[0] <= dt.datetime.now().time():
                print("Its time")
            break
Alarm()
root.mainloop()

print statements are only for testing. The logic I am using in alarm clock is also not executing properly as it tells ""Its time" even after time has passed. I have tried following methods before.

method 1:

for i in reversed(timetable):
    i_time = i
    #print (i_time)
    #print(now_time.strftime("%H:%M"))
    while True:
        if dt.datetime.now().time() < i_time:
        #if i_time <= dt.datetime.now().time():
            print("Its Time")
            break

method 2:

for i in timetable:
    current_time = dt.datetime.now().time()
    alarm_time = i
    while True:
        if current_time < alarm_time:
            if current_time <= alarm_time:
                print("its time", alarm_time)

Using for loop was my first goal but for loop isn't executing properly. It only gets 1st element and doesn't go to 2nd element even if first element has passed so I have decided to go with if,elif,else statement