Date GUI Script Not Changing Properly, Whats wrong!?!?

I'm trying to make a date GUI script and its not working. My date GUI includes Year, Month, And Day. It's not working though, I tried to make it so that when the day reaches day 30 It would change the month to the next one, But I got stuck on that and I don't know how to change it so that when it reaches day 30 it resets back to day one and changes the next month. Then when the month reaches the 12th month then It would be the next year. It takes 5 Seconds then it switches to the next day. I wanted to start my Date at November 11th, 1444. I got stuck and I can't finish the script. Can anyone help guide me so that I can figure out how to do the rest? I have two scripts, The first one is for the day Here it is -

-- This is The Day Script
while true do

script.Parent.Day.Text = script.Parent.Day.Value.Value

local n = script.Parent.Day.Value
n.Value = (n.Value + 1)
    wait(5)
-- Then I got stuck and don't know how to change the month etc...
end

The next script is the Month script, which doesn't work idk Why, after is the year script but I can't figure it out.

-- This Is The Month Script
Z = "January"
X = "February"
C = "March"
V = "April"
B = "May"
L = "June"
M = "July"
J = "August"
H = "September" 
G = "October"
F = "November"
D = "December"

while true do
    script.Parent.Month.Text = script.Parent.Month.Value.Value

    local a = script.Parent.Month.Value
    a.Value = (Z,X,C,V,B,L,M,J,H,G,F,D) 
end

HELP ME!