How to make Lighting.TimeOfDay speed up and slow down?

Here's the code which I'm trying to get to work, but it doesn't quite do what I intended...

From 6:00 to 19:59 it should be +1 From 20:00 to 5:59 it should be + 10

The problem must be the placement of lines, because I'm not getting any errors

l = game:service("Lighting") 

while true do
    repeat
    print("Time changing...")
    wait(0.3)
        l:SetMinutesAfterMidnight(l:GetMinutesAfterMidnight()+1)
        until l:GetMinutesAfterMidnight() >= 1080
        if l:GetMinutesAfterMidnight() >= 1070 then
            repeat
            wait(0.3) 
            l:SetMinutesAfterMidnight(l:GetMinutesAfterMidnight()+10)
            until l:GetMinutesAfterMidnight() >= 560

                if l:GetMinutesAfterMidnight() >= 550 then
                    print'works'
                end
        end
end