Countdwon Clock Surface GUI?

for i = 5*60, 0, -1 do --Here is our four loop; This will begin it's time of 5*60, 5 minutes, or 250 seconds, will count down from -1, or down from 1, until identifier 'i' reaches 0; This will loop until 'i' reaches 0
2	print("Countdown:",i) --This will print into the Output; For each time 'i' goes down from '250', it will print the number into the Output; 'Countdown: 250', 'Countdown: 249', 'Countdown: 248', ect
3	wait(1) --This will wait 1 second before running the code again
4	end --This ends the code block for the 'for' loop

I have this, how do I make it apear on a Surface GUI?

local TimeBoard = game.Workspace["Time"].Timer.Frame.TextLabel
for i = 5*60, 0, -1 do
	TimeBoard.Text = "Countdown:" .. i
	print("Countdown:",i)
	wait(1)
	end