lua 日期与时间操作

require 'math'
require 'os'

dateopt = {}
dateopt_mt = { __index = dateopt }
function dateopt:new()
	local self = {}
	setmetatable(self,dateopt_mt)
	self.year = 1970
	self.month = 1
	self.day = 1
	self.wday = 0
	self.hour = 0
	self.minute = 0
	self.second = 0
	return self
end

function dateopt:init(year,month,day)
	self.year =year
	self.month = month
	self.day = day
end

function dateopt:subDay(opttime)
	local  _days = 0
	local _selfBigger = false
	if (self.year > opttime.year) then
		_selfBigger = true
	elseif  (self.year == opttime.year) then
		if (self.month > opttime.month) then
			_selfBigger = true
		elseif (self.month == opttime.month) then
			if  (self.day > opttime.day) then
				_selfBigger = true
			elseif (self.day == opttime.day) then
				return 0
			end
		end
	end
	local _bigDate = dateopt:new()
	local  _smallDate =dateopt:new()
	if _selfBigger == true then
		_bigDate.year = self.year
		_bigDate.month = self.month
		_bigDate.day = self.day

		_smallDate.year = opttime.year
		_smallDate.month = opttime.month
		_smallDate.day = opttime.day
	else
		_bigDate.year = opttime.year
		_bigDate.month =opttime.month
		_bigDate.day =opttime.day

		_smallDate.year = self.year
		_smallDate.month = self.month
		_smallDate.day = self.day
	end

	for  _i = _smallDate.year, _bigDate.year-1 do
		if((_i % 4 == 0 and _i % 100 ~= 0) or  _i % 400 == 0) then
			_days =_days+366
		else 
			_days = _days+365
		end
	end
	
	for  _i = 1,_smallDate.month-1 do
		if (_i == 1 or _i == 3 or _i == 5 or _i == 7 or _i == 8 or _i == 10 or _i == 12) then
			_days = _days - 31
		elseif (_i == 4 or _i == 6 or _i == 9 or _i == 11) then
			_days =_days - 30
		elseif (_i == 2) then 
			if (_smallDate.year % 4 == 0 and _smallDate.year % 100 ~= 0) or  (_smallDate.year % 400 == 0 ) then
					_days = _days - 29
			else
					_days = _days - 28
			end
		end
	end
	_days =_days- _smallDate.day

	for  _i = 1,_bigDate.month-1 do
		if (_i == 1 or _i == 3 or _i == 5 or _i == 7 or _i == 8 or _i == 10 or _i == 12) then
			_days =_days+31 
		elseif (_i == 4 or _i == 6 or _i == 9 or _i == 11) then
			_days = _days+30  
		elseif _i == 2 then
			if ((_bigDate.year % 4 == 0 and _bigDate.year % 100 ~= 0) or _bigDate.year % 400 == 0)  then
				_days =_days+ 29   
			else     
				_days =_days+28  
			end
		end
	end
	_days = _days+_bigDate.day

	return _days
end


function getCurrentWeekday()
	local weekday = os.date("%w")
	return weekday
end
function getCurrentDate()
	local year= os.date("%Y")	
	local month =os.date("%m")
	local day = os.date("%d")
	
	return year,month,day
end

function get1970ToNow_subdays()
	local Date1 = dateopt:new()
	local Date2 = dateopt:new()
	local year =0
	local month = 0
	local day = 0
	local _nDays = 0
	
	year,month,day = getCurrentDate()
	Date2:init(tonumber(year),tonumber(month),tonumber(day))
	_nDays = Date1:subDay(Date2)
	return _nDays
end



print(get1970ToNow_subdays())
print(getCurrentWeekday())
print(getCurrentDate())