How to get tkinter Spinbox's value?

I am trying to make a timer on python Tkinter. To set the timer, I am using spinboxes. But, I am having trouble getting the value of my spinboxes to be turned into the variables time_h, time_m and time_s.

I have tried .get() but it is not working. When I tried printing the variables I got NameError: name 'spin_h' is not defined.

from tkinter import * 
window = Tk()
window.title("Timer")
window.geometry('350x200')
hour = 0
minute = 0
second = 0
timer = (str(hour) + ':' + str(minute) + ':' + str(second))
lbl = Label(window, text=timer, font=("Arial Bold", 50))
hour_s = 0
min_s = 0
sec_s = 0
def save_time():
    time_h = spin_h.get()
    time_m = spin_m.get()
    time_s = spin_s.get()

def new_window():
    set_time = Tk()
    spin_h = Spinbox(set_time, from_=0, to=10, width=5)
    spin_h.grid(column=1,row=0)
    spin_m = Spinbox(set_time, from_=0, to=60, width=5)
    spin_m.grid(column=3,row=0)
    spin_s = Spinbox(set_time, from_=0, to=60, width=5)
    spin_s.grid(column=5,row=0)
    h_label = Label(set_time, text='h', font=("Arial Bold", 10))
    h_label.grid(column=2, row=0)
    m_label = Label(set_time, text='m', font=("Arial Bold", 10))
    m_label.grid(column=4, row=0)
    s_label = Label(set_time, text='s', font=("Arial Bold", 10))
    s_label.grid(column=6, row=0)
    set_button = Button(set_time, text="Set Time", command=save_time)
    set_button.grid(column=3, row=2)



btn = Button(window, text="Set Time", command=new_window)
btn.grid(column=3, row=2)
lbl.grid(column=3, row=0)
window.mainloop()

spin_h is a variable local to the new_window() function and there cannot be accessed by the save_time() function. You could declare it a global variable at the beginning of new_window() to fix that. - #Martineau (just made it into an answer instead of a comment).

Thanks Martineau