How to fix dates discrepancy between MS SQL Server 2008R2/2012 and Javascript

Question

We store dates in the DB as a diff between the date and '1-Jan-1970' in minutes.

Here're the results from the same machine:

--TSQL (MS Sql Server 2008R2)
SELECT DATEADD(minute, 22572765, '1-Jan-1970'); -- gets 1-Dec-2012 12:45:00.000

//JS (Chrome) - assume minDate = 1-Jan-1970
new Date(minDate.getTime() + (22572765 * 60 * 1000)) -- gets me 1-Jan-2013 12:45:00

What's the best way to solve the discrepancy?

Answer 1

It sounds to me like your minDate is wrong, because this:

new Date((new Date(1970, 0, 1)).getTime() + (22572765 * 60 * 1000))

...gives me 1-Dec-2012 12:45:00.000 GMT.

In JavaScript, the month value is zero-based, so if you're constructing minDate with new Date(1970, 1, 1) , that's why you're a month out.

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Also note that unless you use the UTC variants of things ( getUTCYear , etc.), JavaScript dates will give you the local timezone version of the date on output (your way of constructing the date is correct other than minDate , it's just on output you need to be careful).