>>Why this code bombs on first and 3d line but not on second?
>>

>>? DATE(1430,4,15) && BOOM!!!
>>? ConvertHijriDateToGregorianDate(DATE(1430,4,15)) && Fine
>>? ConvertGregorianDateToHijriDate(DATE(2009,4,11)) && BOOM!!!
>>
>>Function ConvertHijriDateToGregorianDate(ldHijriDate)
>>    d = DAY(ldHijriDate)
>>    m = MONTH(ldHijriDate)
>>    y = YEAR(ldHijriDate)
>>    jd = INT((11 * m.y + 3) / 30) + 354 * m.y + 30 * m.m - INT((m.m- 1 )/ 2) + m.d + 1948440 - 385
>>    IF (m.jd > 2299160 )
>>       l = m.jd + 68569
>>       n = INT((4 * m.l) / 146097)
>>       l = m.l - INT((146097 * m.n + 3) / 4)
>>       i = INT((4000*(m.l+1)) / 1461001)
>>       l = m.l - INT((1461*m.i)/4)+31
>>       j = INT((80*m.l)/2447)
>>       d = l-INT((2447*m.j)/80)
>>       l = INT(m.j/11)
>>       m = m.j+2-12*l
>>       y = 100*(m.n-49)+m.i+m.l
>>    ELSE
>>       j = m.jd + 1402
>>       k = INT(m.j-1)/1461)
>>       l = m.j-1461*m.k
>>       n = INT((m.l-1)/365)-INT(m.l/1461)
>>       i = m.l-365*n+30
>>       j = INT((80*m.i)/2447)
>>       d = i-INT((2447*m.j)/80)
>>       i = INT(m.j/11)
>>       m = m.j+2-12*m.i
>>       y = 4*m.k+m.n+m.i-4716
>>    ENDIF
>>   
>>RETURN DATE(m.y, m.m, m.d)
>>
>>Function ConvertGregorianDateToHijriDate(ldGregorianDate)
>>    d = DAY(ldGregorianDate)
>>    m = MONTH(ldGregorianDate)
>>    y = YEAR(ldGregorianDate)
>>    IF ldGregorianDate > DATE(1582,10,14)
>>       jd = INT((1461*(m.y+4800+INT((m.m-14)/12)))/4)+;
>>            INT((367*(m.m-2-12*(INT((m.m-14)/12))))/12)-;
>>            INT( (3* (INT(  (m.y+4900+INT((m.m-14)/12))/100)))/4)+m.d-32075
>>    ELSE
>>       jd = 367*m.y-INT((7*(m.y+5001+INT((m.m-9)/7)))/4)+INT((275*m.m)/9)+m.d+1729777
>>    ENDIF
>>    l = m.jd - 1948440 + 10632
>>    n = INT((m.l-1)/10631)
>>    l = m.l-10631*m.n+354
>>    j = (INT((10985-m.l)/5316))*(INT((50*m.l)/17719))+(INT(m.l/5670))*(INT((43*m.l)/15238))
>>    l = m.l - (INT((30-m.j)/15))*(INT((17719*m.j)/50))-(INT(j/16))*(INT((15238*m.j)/43))+29
>>    m = INT((24*m.l)/709)
>>    d = m.l - INT((709*m.m)/24)
>>    y = 30 * m.n + m.j - 30
>>    ? m.y, m.m, m.d
>>RETURN DATE(m.y, m.m, m.d)
>>

>>
>>I try to convert a JAVA script from here:http://www.mela.us/committees/hegira.html to VFP The first function works (at least it not bombs) but the second gives me "Date/Datetime evaluated to invalid value".
>>How's that?
>>If 15 Apr. (or whatever name it is) 1430 is invalid why VFP not bombs when I sent it as parameter?
>
>I only tried the first line of your code, but it does not crash or error in VFP9 SP1.
>
>It works with all 3 settings of STRICTDATE. What is your SET DATE?

GERMAN.

THIS CAN'T BE TRUE!!!!!!!!!
I changed SET DATE AMERICAN and it works!!!
After that I changed SET DATE GERMAN and IT WORKS again!!!!!!!!!!
I restarted VFP and start the code and IT BOMBS again until I changed the date to AMERICAN and then back to GERMAN.


UPDATE:
That code works every time:

CLEAR
SET DATE AMERICAN 
SET DATE GERMAN
? DATE(1430,4,15)
? ConvertHijriDateToGregorianDate(DATE(1430,4,15))
? ConvertGregorianDateToHijriDate(DATE(2009,4,11))

Function ConvertHijriDateToGregorianDate(ldHijriDate)
    d = DAY(ldHijriDate)
    m = MONTH(ldHijriDate)
    y = YEAR(ldHijriDate)
    jd = INT((11 * m.y + 3) / 30) + 354 * m.y + 30 * m.m - INT((m.m- 1 )/ 2) + m.d + 1948440 - 385
    IF (m.jd > 2299160 )
       l = m.jd + 68569
       n = INT((4 * m.l) / 146097)
       l = m.l - INT((146097 * m.n + 3) / 4)
       i = INT((4000*(m.l+1)) / 1461001)
       l = m.l - INT((1461*m.i)/4)+31
       j = INT((80*m.l)/2447)
       d = l-INT((2447*m.j)/80)
       l = INT(m.j/11)
       m = m.j+2-12*l
       y = 100*(m.n-49)+m.i+m.l
    ELSE
       j = m.jd + 1402
       k = INT((m.j-1)/1461)
       l = m.j-1461*m.k
       n = INT((m.l-1)/365)-INT(m.l/1461)
       i = m.l-365*n+30
       j = INT((80*m.i)/2447)
       d = i-INT((2447*m.j)/80)
       i = INT(m.j/11)
       m = m.j+2-12*m.i
       y = 4*m.k+m.n+m.i-4716
    ENDIF
   
RETURN DATE(m.y, m.m, m.d)

Function ConvertGregorianDateToHijriDate(ldGregorianDate)
ASSERT .f. 
    d = DAY(ldGregorianDate)
    m = MONTH(ldGregorianDate)
    y = YEAR(ldGregorianDate)
    IF ldGregorianDate > DATE(1582,10,14)
       jd = INT((1461*(m.y+4800+INT((m.m-14)/12)))/4)+;
            INT((367*(m.m-2-12*(INT((m.m-14)/12))))/12)-;
            INT( (3* (INT(  (m.y+4900+INT((m.m-14)/12))/100)))/4)+m.d-32075
    ELSE
       jd = 367*m.y-INT((7*(m.y+5001+INT((m.m-9)/7)))/4)+INT((275*m.m)/9)+m.d+1729777
    ENDIF
    l = m.jd - 1948440 + 10632
    n = INT((m.l-1)/10631)
    l = m.l-10631*m.n+354
    j = (INT((10985-m.l)/5316))*(INT((50*m.l)/17719))+(INT(m.l/5670))*(INT((43*m.l)/15238))
    l = m.l - (INT((30-m.j)/15))*(INT((17719*m.j)/50))-(INT(j/16))*(INT((15238*m.j)/43))+29
    m = INT((24*m.l)/709)
    d = m.l - INT((709*m.m)/24)
    y = 30 * m.n + m.j - 30
    ? m.y, m.m, m.d
RETURN DATE(m.y, m.m, m.d)