In his blog, prof. Thomas Djamaluddin, a researcher in LAPAN (Indonesia's National Institute of Aeronautics and Space) posted a small program to do a conversion between a Solar date to a Hijri date, and vice versa. Here is the translated version of his program, written in Python programming language. The original paper of prof. Thomas regarding the program can downloaded here.
Hope this small program is useful.
def main():
print "*** Calendar Conversion Program ***"
print " Hijri (Islamic Calendar) <-> Solar Calendar "
print " (Caution: There is the Islamic Date Line which"
print " causes this calculation may differ about (+/-) 1 day)."
print " 6 August 1991, 25 Muharram 1412"
print " Calculated by T.Djamaluddin"
print " Dept. of Astronomy, Kyoto University"
print " Sakyo-Ku, Kyoto 606, Japan"
print "*******"
print ""
conv = ""
while conv <> 0:
print "1. Conversion Hijri (Islamic Calendar) to Solar Calendar"
print "2. Conversion Solar Calendar to Hijri (Islamic Calendar)"
print ""
conv = input("Choose 1 or 2 (0 to exit):")
if (conv == 1):
hijriToSolarMenu()
elif (conv == 2):
solarToHijriMenu()
else:
pass
def hijriToSolarMenu():
'''
Ask user to enter (assume valid) Hijri date. Calls
hijriToSolar().
'''
print "*** Conversion from Hijri to Solar Calendar ***"
print ""
hd = input("Hijri date:")
print "1. Muharram 5. Jumadil Awal 9. Ramadhan"
print "2. Safar 6. Jumadil Akhir 10. Syawal"
print "3. Rabiul Awal 7. Rajab 11. Zulqaidah"
print "4. Rabiul Akhir 8. Shaban 12. Zulhijjah"
hm = input("Hijri month:")
hy = input("Hijri year:")
(sd, sm, sy) = hijriToSolar(hd, hm, hy)
smStr = solarMonthName(sm)
print hd,"/",hm,"/",hy, "Hijri is", sd,"/",sm,"/",sy, "A.D.","(",smStr,")"
def hijriToSolar(hd, hm, hy):
'''
Converts a given Hijri date to Solar date.
'''
nhd1 = (hy - 1) * 354.3671 + (hm - 1) * 29.5306 + hd
nhd = int(nhd1)
nsd = nhd1 + 227016
if nhd > 350721:
gc = 10
else:
gc = 0
if nhd > 393898:
gc = 11
if nhd > 430422:
gc = 12
if nhd > 466946:
gc = 13
sy = int( (nsd + gc)/365.25) + 1
mn = round((nsd+gc)-(sy-1)*365.25)
mn1 = 0
sm = 1
if mn > 31:
mn1 = 31
sm = 2
if int(sy/4) == (sy/4):
(mn1, sm) = leapYear(mn, mn1, sm)
else:
(mn1, sm) = ordinaryYear(mn, mn1, sm)
if sy == 1700 or sy == 1800:
(mn1, sm) = ordinaryYear(mn, mn1, sm)
if sy == 1900:
(mn1, sm) = ordinaryYear(mn, mn1, sm)
smStr = solarMonthName(sm)
sd = int(mn - mn1)
return (sd, sm, sy)
def solarMonthName(sm):
'''
Given a month number 'sm', returns its corresponding solar month name.
'''
# Result
if sm == 1:
smStr = " January "
if sm == 2:
smStr = " February "
if sm == 3:
smStr = " March "
if sm == 4:
smStr = " April "
if sm == 5:
smStr = " May "
if sm == 6:
smStr = " June "
if sm == 7:
smStr = " July "
if sm == 8:
smStr = " August "
if sm == 9:
smStr = " September "
if sm == 10:
smStr = " October "
if sm == 11:
smStr = " November "
if sm == 12:
smStr = " December "
return smStr
def leapYear(mn, mn1, sm):
'''
# Leap (Kabisat) Year
'''
if mn > 60:
mn1 = 60
sm = 3
if mn > 91:
mn1 = 91
sm = 4
if mn > 121:
mn1 = 121
sm = 5
if mn > 152:
mn1 = 152
sm = 6
if mn > 182:
mn1 = 182
sm = 7
if mn > 213:
mn1 = 213
sm = 8
if mn > 244:
mn1 = 244
sm = 9
if mn > 274:
mn1 = 274
sm = 10
if mn > 335:
mn1 = 305
sm = 11
if mn > 335:
mn1 = 335
sm = 12
return (mn1, sm)
def ordinaryYear(mn, mn1, sm):
'''
# Ordinary (Basitah) Year
'''
if mn > 59:
mn1 = 59
sm = 3
if mn > 90:
mn1 = 90
sm = 4
if mn > 120:
mn1 = 120
sm = 5
if mn > 151:
mn1 = 151
sm = 6
if mn > 181:
mn1 = 181
sm = 7
if mn > 212:
mn1 = 212
sm = 8
if mn > 243:
mn1 = 243
sm = 9
if mn > 273:
mn1 = 273
sm = 10
if mn > 304:
mn1 = 304
sm = 11
if mn > 334:
mn1 = 334
sm = 12
return (mn1, sm)
def solarToHijriMenu():
'''
Ask user to enter (assume valid) Gregorian date. Calls
solarToHijri().
'''
print "*** Solar Calendar to Hijri ***"
sd = input("Solar date:")
print "1. January 5. May 9. September"
print "2. February 6. June 10. October"
print "3. March 7. July 11. November"
print "4. April 8. August 12. December"
sm = input("Solar month:")
sy = input("Solar year:")
(hd, hm, hy) = solarToHijri(sd, sm, sy)
ddStr = hijriMonthName(hm)
print sd,"/",sm,"/",sy, "A.D. is", hd,"/",hm,"/",hy, "Hijri (", ddStr, ")"
def solarToHijri(sd, sm, sy):
'''
Calculates a Hijri date to Solar date.
'''
if sm == 1:
mn = 0
if sm == 2:
mn = 31
if sm == 3:
mn = 59
if sm == 4:
mn = 90
if sm == 5:
mn = 120
if sm == 6:
mn = 151
if sm == 7:
mn = 181
if sm == 8:
mn = 212
if sm == 9:
mn = 243
if sm == 10:
mn = 273
if sm == 11:
mn = 304
if sm == 12:
mn = 334
y = sy + (mn + sd)/ 365.25
if y > 1582.76 and y < 1582.788:
print "Gregorian: Omitted"
return None
else:
if y > 1582.76:
gc = 10
else:
gc = 0
if y > 1701:
gc = 11
if y > 1801:
gc = 12
if y > 1901:
gc = 13
ydn = (sy - 1) * 365.25
if sm < 3:
pass
else:
if int(sy/4) == (sy/4):
mn = mn + 1
if sy == 1700:
mn = mn - 1
if sy == 1800 or sy == 1900:
mn = mn - 1
nsd = ydn + mn + sd - gc
nhd1 = nsd - 227016
nhd = int(nhd1)
hy = int(nhd1/354.3671 + 1)
hm1 = round(nhd1 - (hy - 1) * 354.3671)
hm = int(hm1/29.5306) + 1
hd = int(round(hm1 - (hm - 1) * 29.5306))
ddStr = weekDayName(nhd)
if hd == 0:
hm = hm - 1
hd = 30
hmStr = hijriMonthName(hm)
# Result
if hm == 0:
hmStr = " Zulhijjah "
hy = hy - 1
if hm == 1:
hmStr = " Muharram "
if hm == 2:
hmStr = " Safar "
if hm == 3:
hmStr = " Rabiul Awal "
if hm == 4:
hmStr = " Rabiul Akhir "
if hm == 5:
hmStr = " Jumadil Awal "
if hm == 6:
hmStr = " Jumadil Akhir "
if hm == 7:
hmStr = " Rajab "
if hm == 8:
hmStr = " Shaban "
if hm == 9:
hmStr = " Ramadhan "
if hm == 10:
hmStr = " Shawal "
if hm == 11:
hmStr = " Zulqaidah "
if hm == 12:
hmStr = " Zulhijjah "
return (hd, hm, hy)
def hijriMonthName(hm):
'''
Given a Hijri month number 'hm', returns corresponding Hijri month name.
'''
# Result
if hm == 0:
hmStr = " Zulhijjah "
hy = hy - 1
if hm == 1:
hmStr = " Muharram "
if hm == 2:
hmStr = " Safar "
if hm == 3:
hmStr = " Rabiul Awal "
if hm == 4:
hmStr = " Rabiul Akhir "
if hm == 5:
hmStr = " Jumadil Awal "
if hm == 6:
hmStr = " Jumadil Akhir "
if hm == 7:
hmStr = " Rajab "
if hm == 8:
hmStr = " Shaban "
if hm == 9:
hmStr = " Ramadhan "
if hm == 10:
hmStr = " Shawal "
if hm == 11:
hmStr = " Zulqaidah "
if hm == 12:
hmStr = " Zulhijjah "
return hmStr
def weekDayName(nhd):
'''
Given an integer 'nhd', returns the name of the weekday.
'''
nhd1 = nhd - 7 * int(nhd/7)
dd = nhd1 % 7
if dd == 0:
ddStr = " Thursday "
if dd == 1:
ddStr = " Friday "
if dd == 2:
ddStr = " Saturday "
if dd == 3:
ddStr = " Sunday "
if dd == 4:
ddStr = " Monday "
if dd == 5:
ddStr = " Tuesday "
if dd == 6:
ddStr = " Wednesday "
return ddStr
if __name__ == '__main__':
main()
