昼夜轮转：入夜开启夜间玩法

-- 错误：各玩法自己看真实时间，口径不一
function onTick()
    if tonumber(os.date("%H")) >= 20 then
        openNightPlay()
    end
end

local DAY_REAL = 2 * 3600
local function gameHour()
    local sec = os.time() % DAY_REAL
    return math.floor(sec / DAY_REAL * 24)
end
local function onTick()
    local h = gameHour()
    local night = h >= 18 or h < 5
    if night ~= getSysNight() then
        setSysNight(night)
        broadcast(night and "夜幕降临"
            or "天色渐亮")
    end
end