How would I fix this timer script?

Basically, I need to script to be a timer script that's the same for everyone, not local. I'm currently experiencing problems that whenever I reset/die, the time resets back to its full time. How would I make it so the time is the same for all the players, I tried creating an IntValue, but it's not working. Script below...

t=game.Workspace:FindFirstChild("Timer").Value
while true do
wait()
t=t+30
for i=1, 30 do
    t=t-1
    wait(1)
    for i, player in pairs(game.Players:GetPlayers()) do
    player.PlayerGui.TimerSet.Frame.Time.Text=tostring(t) 
end
end

t=t+45
for i=1, 45 do
    t=t-1
    wait(1)
    for i, player in pairs(game.Players:GetPlayers()) do
    player.PlayerGui.TimerSet.Frame.Time.Text=tostring(t)
end
end
for i, player in pairs(game.Players:GetPlayers()) do
player.Character.Humanoid.Health = 0
player.Character.Humanoid.MaxHealth = 0
end
end

Thanks!

I just made a bit more simple. I don't like to rely on objects outside of scripts so I just put the variable inside of the script:

function newTimer(length)
	for i=length, 0, -1 do
		for j,p in pairs(game.Players:GetPlayers()) do
			if p.PlayerGui ~= nil then
				p.PlayerGui.TimerSet.Frame.Time.Text=i;
			end
		end
		wait(1);
	end
end

while true do
	newTimer(30);
	newTimer(45);
	for i,p in pairs(game.Players:GetPlayers()) do
		if p.Character.Humanoid ~= nil then
			p.Character.Humanoid.Health = 0;
		end
	end
end