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newuser_ca

70 Posts

Posted - 07/26/2012 : 2:15:55 PM

OriginPro 8.6 in Win7

I have a dataset contains Julian Day value as "Date" column. But when I import and convert the date, I have 12-hour offset in Origin.

I noticed that the Julian Day value in Origin is not the same as I got from wiki.
Example: Julian Day Value = 2456135
I use the following codes in Origin to conver to string:
double jd = 2456135;
out_str(get_date_str(jd, LDF_SHORT_AND_HHMM_SEPARCOLON));

The result I got in Origin is: "7/27/2012 00:00"

I used some converters in the Internet, I got "2012 July 26 12:00:00". There is a 12-hour difference.

I searched in the Internet. The Julian Day in wiki is 12h Jan 1, 4713 BC (http://en.wikipedia.org/wiki/Julian_day)

It seems to me that the Julian Day value in Origin counts from 0h instead of 12h.

Is this a bug in Origin or is it set as this way?

Thanks.

Penn

China
644 Posts

Posted - 07/27/2012 : 01:54:57 AM

Hi,

Actually, Origin uses a 12 hour offset in order to have 0 hours coincide with midnight. So, the result should be correct.

Penn