Mon, 10/16/2017 - 16:30
Hi,
Thought I'd cracked this, but obviously not!
While reporting my obs 2 nights ago using the charting/reporting tool I have written, the JD was 1 day too late, and I have also had a reply to the same effect by my one and only user so far. Here is what I am using (VB6) which comes from this forum ex Meeus, with small changes - I don't need negative dates for obvious reasons! Below gives just the julian day - the decimal of the time is added to the result.
Public Function julian(Y As Integer, m As Integer, d As Integer) As Long
Dim a As Integer, b As Integer
a = Int(Y / 100)
b = 2 - a + Int(a / 4)
If m > 2 Then
'do nothing
Else
Y = Y - 1
m = m + 12
End If
julian = Int(365.25 * (Y + 4716)) + Int(30.6001 * (m + 1)) + d + b - 1524.5
End Function
Happy to compare notes with my implementation. Looks very much the same as:
https://sourceforge.net/p/vstar/code/HEAD/tree/trunk/src/org/aavso/tools/vstar/util/date/MeeusDateUtil.java
https://sourceforge.net/p/vstar/code/HEAD/tree/trunk/test/org/aavso/tools/vstar/util/date/DateUtilTestBase.java
If you want to compare results of specific date tests, let me know.
David
Thanks David, looks as though you include the day (decimal and all) as one of the parameters, whereas I add it on after the 'integer' JD (without decimal) has been returned. Could be that's what is giving me the wrong result, so I shall give that a try. Many thanks.
Hi Michael
Yep, that makes sense. When I looked quickly at your code above I didn't notice the integer type for day in your function's parameter list. As you say, mine isĀ of a real type:
David
Hi David,
Yes, that did it! Just ran the new code and everything correct to 4 dp. Cheers!
Glad to help Michael.
David