（原創）lua日期、時間、時間戳的計算和轉換

----------------------------------------------日期與時間
print("當前時間戳：")
local nowTime = os.time()
print(nowTime)

print("")
print("轉換成日期：")
--時間戳 轉 日期
local nowData = os.date("%Y%m%d%H%M%S",nowTime)
print(nowData)

--可以單獨轉換
local tb = {}
tb.year = tonumber(os.date("%Y",unixTime))
tb.month =tonumber(os.date("%m",unixTime))
tb.day = tonumber(os.date("%d",unixTime))
tb.hour = tonumber(os.date("%H",unixTime))
tb.minute = tonumber(os.date("%M",unixTime))
tb.second = tonumber(os.date("%S",unixTime))

--轉成table
local tb = os.date("*t",nowTime)
dump(tb)

print("")
print("日期轉回時間戳：")
print(os.time(tb))



print("")

local time1 = os.time({year=2018,month=2,day=28,hour=23, min=0, sec=3})
local time2 = os.time({year=2018,month=3,day=1,hour=1, min=0, sec=2})


print("獲取時間戳對應的日期")
--獲取時間戳對應的天數（天數規則不是自然天，是(hour)4點前當前一天算）
function Tool:GetDayKeyByUnixTime(unixTime,hour)
    if hour == nil then hour = 0 end
    local retStr = os.date("%Y-%m-%d %H:%M:%S",unixTime)
    local time = unixTime
    local data = os.date("*t",time)
    --dump(data)

    --(hour)4點前按前一天算
    if data.hour < hour then
        time = time - 24*60*60        
    end

    local data2 = os.date("*t",time)
    --dump(data2)
    data2.hour = 0
    data2.min = 0
    data2.sec = 0

    local time2 = os.time(data2)

    local dayKey = os.date("Key%Y%m%d",time2)
    local timeBase = time2

    --天數key，日期格式字符串，天數key 0點的時間戳
    return dayKey,retStr,timeBase
end

local dayKey,str = Tool:GetDayKeyByUnixTime(time1,4)
print("dayKey = "..dayKey.."  str = "..str)
dayKey,str = Tool:GetDayKeyByUnixTime(time2,4)
print("dayKey = "..dayKey.."  str = "..str)


--兩個時間的天數差              --時間戳1  時間戳2  多少點開始算第二天
function Tool:NumberOfDaysInterval(unixTime1,unixTime2,dayFlagHour)
    if dayFlagHour == nil then dayFlagHour = 0 end
    local key1,str1,time1 = Tool:GetDayKeyByUnixTime(unixTime1,dayFlagHour)
    local key2,str2,time2 = Tool:GetDayKeyByUnixTime(unixTime2,dayFlagHour)

    local sub = math.abs(time2 - time1)/(24*60*60)
    print(str1.." 與 "..str2.."相差的天數："..sub)

    return sub
end

local sub = Tool:NumberOfDaysInterval(time1,time2,4)
print(sub)