PointLight is not a valid member of Part?

So, I'm making a light the will follow the day/night cycle. Turns on at 6 AM, turns off at 6 PM. However, whenever it reaches 6 PM, the code will stop and say the following:

22:09:47.594 - Pointlight is not a valid member of Part 22:09:47.595 - Script 'ServerScriptService.Script', Line 12 22:09:47.596 - Stack End

lightPart = game.Workspace.LightPart
minutesAfterMidnight = 0
while true do
	minutesAfterMidnight = minutesAfterMidnight + 10
	game.Lighting:SetMinutesAfterMidnight(minutesAfterMidnight)
 	wait(.1)

 	if game.Lighting:GetMinutesAfterMidnight() == 18 * 60 then
		lightPart.Material = Enum.Material.Neon
		lightPart.Pointlight.Enabled = true
	end
	if game.Lighting:GetMinutesAfterMidnight() == 6 * 60 then
		lightPart.Material = Enum.Material.Plastic
		lightPart.PointLight.Enabled = false
	end
end

It says line 12, but in this block of code, it's line 10. I don't see anywhere where this error could have occurred. Help is appreciated. Thanks.

I Don't know if this solves your problem, but

lightPart = game.Workspace:WaitForChild('LightPart') -- Used a better method, than just 'workspace.LightPart' which is 'WaitForChild' which waits until the object is found
Light = lightPart:WaitForChild('PointLight') -- Used to wait until PointLight is found
minutesAfterMidnight = 0
while true do
    minutesAfterMidnight = minutesAfterMidnight + 10
    game.Lighting:SetMinutesAfterMidnight(minutesAfterMidnight)
    wait(.1)

    if game.Lighting:GetMinutesAfterMidnight() == 18 * 60 then
        lightPart.Material = Enum.Material.Neon
      Light.Enabled = true
    end
    if game.Lighting:GetMinutesAfterMidnight() == 6 * 60 then
        lightPart.Material = Enum.Material.Plastic
        Light.Enabled = false
    end
end