How to turn seconds into minutes and seconds? (00:00)

Hello. I have recently been making a game with a round system. The game works fine and everything, though I only have one "issue".

The seconds left of the round (on the GUI) are only in seconds. I want it to say how many minutes and seconds (like the 00:00 format) the round has left. Here's the round script:

local roundLength = 1805
local intermissionLength = 40
local InRound = game.ReplicatedStorage.InRound
local Status = game.ReplicatedStorage.Status

local LobbySpawn = game.Workspace.LobbySpawn
local GameAreaSpawn = game.Workspace.GameAreaSpawn

InRound.Changed:Connect(function()
    wait(1)
    if InRound.Value == true then
        for _, player in pairs(game.Players:GetChildren()) do
            local char = player.Character
            char.HumanoidRootPart.CFrame = GameAreaSpawn.CFrame
        end
    else
        for _, player in pairs(game.Players:GetChildren()) do
            local char = player.Character
            char.HumanoidRootPart.CFrame = LobbySpawn.CFrame
        end

    end
end)




local function roundTimer()
    while wait() do
        for i = intermissionLength, 1, -1 do
            InRound.Value = false
            wait(1)
            Status.Value = "Game starts in ".. i .."..."        
        end
        for i = roundLength, 1, -1 do
            InRound.Value = true
            wait(1)
            Status.Value = i
        end 
    end
end

spawn(roundTimer)

As you see, I would like the 1805 seconds to be turned into 30:05 minutes. I'm not sure where to put the code, nor how to script it.

Any help is appreciated!