"A leaderboard that counts your time on how long you have been on the server for. by every minute and save the time of the player when they leave the game"

-- server script (ServerScriptService) 
local Players = game:GetService("Players")
local DataStoreService = game:GetService("DataStoreService")
local timeDataStore = DataStoreService:GetDataStore("PlayerTime")

local function onPlayerAdded(player)
    local leaderstats = Instance.new("Folder")
    leaderstats.Name = "leaderstats"
    leaderstats.Parent = player

local TimePlayed = Instance.new("IntValue")
    TimePlayed.Name = "TimePlayed"
    TimePlayed.Parent = leaderstats

local data
    local success, errorMessage = pcall(function()
        data = timeDataStore:GetAsync(player.UserId)
    end)

if success and data then
        TimePlayed.Value = data
    end

while player do
        wait(60)
        TimePlayed.Value = TimePlayed.Value + 1
    end
end

local function onPlayerRemoving(player)
    local timePlayed = player.leaderstats.TimePlayed.Value
    local success, errorMessage = pcall(function()
        timeDataStore:SetAsync(player.UserId, timePlayed)
    end)

if not success then
        warn("Failed to save time data for player: " .. player.Name)
    end
end

Players.PlayerAdded:Connect(onPlayerAdded)
Players.PlayerRemoving:Connect(onPlayerRemoving)

for _, player in ipairs(Players:GetPlayers()) do
    onPlayerAdded(player)
end