DateTime

local now = DateTime.CurrentTime({isLocal = true})
print(tostring(now))
print(now:ToIsoString())

local function OnPlayerLeft(player)
    local data = Storage.GetPlayerData(player)

    local now = DateTime.CurrentTime()
    data.leftDateTime = now:ToIsoString()

    Storage.SetPlayerData(player, data)
end

local function OnPlayerJoined(player)
    local data = Storage.GetPlayerData(player)

    if data.leftDateTime then
        local leftAt = DateTime.FromIsoString(data.leftDateTime)
        local now = DateTime.CurrentTime()
        local secondsElapsed = now.secondsSinceEpoch - leftAt.secondsSinceEpoch
        print("player ".. player.name .." was away for "..secondsElapsed.." seconds.")
    else
        print("New player ".. player.name ..". First time playing.")
    end
end

Game.playerLeftEvent:Connect(OnPlayerLeft)
Game.playerJoinedEvent:Connect(OnPlayerJoined)

local UI_TEXT = script:GetCustomProperty("UITextBox"):WaitForObject()

function FormatDigitalTime(dateTime)
    -- Hour
    local str = dateTime.hour .. ":"
    -- Minutes
    if dateTime.minute < 10 then
        str = str .. "0"
    end
    str = str .. dateTime.minute .. ":"
    -- Seconds
    if dateTime.second < 10 then
        str = str .. "0"
    end
    str = str .. dateTime.second
    return str
end

function Tick()
    local now = DateTime.CurrentTime({isLocal = true})
    UI_TEXT.text = FormatDigitalTime(now)

    Task.Wait(1)
end

local SECONDS_IN_DAY = 60 * 60 * 24

-- This function takes a number of remaining seconds and formats it into a string
local function FormatCasualTimespan(totalSeconds)
    local seconds = totalSeconds
    local minutes = math.floor(seconds / 60)
    seconds = seconds - minutes*60

    if minutes > 0 then
        local hours = math.floor(minutes / 60)
        minutes = minutes - hours*60

        if hours > 0 then
            local days = math.floor(hours / 24)
            hours = hours - days*24

            if days > 0 then
                if hours > 0 then
                    return days.."d " .. hours.."h"
                end
                return days.."d"

            elseif (minutes > 0) then
                return hours.."h " .. minutes.."m"
            end
            return hours.."h"
        end
        return minutes.."m " .. seconds.."s"
    end
    return seconds.."s"
end

-- Calculate when is the next midnight
local now = DateTime.CurrentTime()
local tomorrow = DateTime.FromSecondsSinceEpoch(now.secondsSinceEpoch + SECONDS_IN_DAY)
local nextMidnight = DateTime.New({
    year = tomorrow.year,
    month = tomorrow.month,
    day = tomorrow.day,
    hour = 0
})
-- Print to the Event Log how much time remains until midnight
local secondsUntilMidnight = nextMidnight.secondsSinceEpoch - now.secondsSinceEpoch
print("Time until midnight: " .. FormatCasualTimespan(secondsUntilMidnight))