b = script.Parent

local oh,om = 6,30	-- Daytime
local ch,cm = 17,30	-- Nighttime

local l = game:service("Lighting")
if (om == nil) then om = 0 end
if (cm == nil) then cm = 0 end


function TimeChanged()
	local ot = (oh + (om/60)) * 60
	local ct = (ch + (cm/60)) * 60
	if (ot < ct) then
		if (l:GetMinutesAfterMidnight() >= ot) and (l:GetMinutesAfterMidnight() <= ct) then
			b.Material = "SmoothPlastic"
			b.Reflectance = "0.45"
			b.Color = Color3.new(0.47451, 0.482353, 0.513725)
			b.PointLight.Enabled = false
		else
			b.Material = "Neon"
			b.Reflectance = "0"
			b.Color = Color3.new(0.639216, 0.576471, 0.454902)
			b.PointLight.Enabled = true
		end
	elseif (ot > ct) then
		if (l:GetMinutesAfterMidnight() >= ot) or (l:GetMinutesAfterMidnight() <= ct) then
b.Transparency = 0
		else
b.Transparency = 0
		end
	end
end

TimeChanged()
game.Lighting.Changed:connect(function(property)
			if (property == "TimeOfDay") then
				TimeChanged()
			end
		end)

The current version above fully works but for it to work the script itself has to be inside each individual part/union.

I want to try make it so a single script changes multiple parts/lights so lag ins't too bad.

I know it has something to do with :GetChildren but i'm unsure of how to set this up and have tried multiple times by reading through the devforum as well as youtube.

Appreciate the help!

try changing it to this

local oh,om = 6,30  -- Daytime
local ch,cm = 17,30 -- Nighttime

local l = game:service("Lighting")
if (om == nil) then om = 0 end
if (cm == nil) then cm = 0 end


function TimeChanged(b)
    local ot = (oh + (om/60)) * 60
    local ct = (ch + (cm/60)) * 60
    if (ot < ct) then
        if (l:GetMinutesAfterMidnight() >= ot) and (l:GetMinutesAfterMidnight() <= ct) then
            b.Material = "SmoothPlastic"
            b.Reflectance = "0.45"
            b.Color = Color3.new(0.47451, 0.482353, 0.513725)
            b.PointLight.Enabled = false
        else
            b.Material = "Neon"
            b.Reflectance = "0"
            b.Color = Color3.new(0.639216, 0.576471, 0.454902)
            b.PointLight.Enabled = true
        end
    elseif (ot > ct) then
        if (l:GetMinutesAfterMidnight() >= ot) or (l:GetMinutesAfterMidnight() <= ct) then
b.Transparency = 0
        else
b.Transparency = 0
        end
    end
end

TimeChanged()
game.Lighting.Changed:connect(function(property)
            if (property == "TimeOfDay") then
                for i,b in pairs(script.Parent:GetChildren()) do
			TimeChanged(b)
		end
            end
        end)

if it doesn't work then maybe try changing

for i,b in pairs(script.Parent:GetChildren()) do
	TimeChanged(b)
end

to

for i,b in next, script.Parent:GetChildren() do
	TimeChanged(b)
end