使用javascript将SQL日期数字转换为日期

Question

Gabriele Petrioli please read my question before you close it.

my reports in SQL are daily, and INT as Date is perfect, two years ago I test Azure CosmosDB and I was able to convert by using JavaScript I did it by using UDF I just needed now for a project and bad luck, can't believe so many people are involved to downplay questions and administrating without programming skills and "managing", I will do it again I will not give up but I need the code today. I will post the solution if the managers did not close my question again.

here the original question:

I need to convert INT date produced by SQL into a Date using javascript.

I know this is possible I did it before I have a terrible day today and the time is clicking.

Here is the process: I convert the date to INT using SQL

select 'cast(getdate() as  int)'
select cast(getdate()  as  int)
-- today 43811

I need to bring it back using Javascript. No Jquery or else.

--more exaples
select 'cast(40702 as  smalldatetime)'
select cast(40702 as  smalldatetime)
--output 2011-06-10 00:00:00


select 'cast(getdate() as  float)'
select cast(getdate()  as  float)
-- output 43810.6597960262

Again I need to use JavaScript
convert2date(40702) --> 2011-06-10

convert2date(43811) --> 2019-12-14

Answer 1

What you have is a day count from 1900-01-01 and you need to add the given days.

 function convert2date(days) { const isLeapYear = year => (!(year % 4) && !!(year % 100)) || !(year % 400), daysInMonth = (month, year) => [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31][month - 1] + isLeapYear(year); var date = [1900, 1, 1], y = isLeapYear(date[0]) + 365, d; while (days >= y) { date[0]++; days -= y; y = isLeapYear(date[0]) + 365; } d = daysInMonth(date[1], date[0]); while (days >= d) { date[1]++; days -= d; d = daysInMonth(date[1], date[0]); } date[2] += days; return date.map((v, i) => v.toString().padStart(i ? 2 : 4, 0)).join('-'); } console.log(convert2date(40702)); // 2011-06-10 console.log(convert2date(43811)); // 2019-12-14