diff --git a/tests/test_tools.py b/tests/test_tools.py
new file mode 100644
index 0000000000000000000000000000000000000000..2bffc7ecbb0adb5e5858657efebd4a785b30afb8
--- /dev/null
+++ b/tests/test_tools.py
@@ -0,0 +1,23 @@
+import unittest
+from datetime import datetime
+import tools
+
+
+class ToolsTests(unittest.TestCase):
+    def test_julian2dt(self):
+        """
+        Tests a simple of julian day 0, origine 1950
+        """
+        dt = datetime(year=1950, day=1, month=1)
+
+        self.assertAlmostEqual(0, tools.dt2julian(dt))
+        
+    def test_dt2julian(self):
+        
+        dt = tools.julian2dt(0)
+        self.assertEqual(dt.year, 1950)
+        self.assertEqual(dt.month, 1)
+        self.assertEqual(dt.day, 1)
+        self.assertEqual(dt.hour, 0)
+        self.assertEqual(dt.minute, 0)
+        self.assertEqual(dt.second, 0)
\ No newline at end of file
diff --git a/tools.py b/tools.py
new file mode 100644
index 0000000000000000000000000000000000000000..0786971a06ff76f6382a04f1c43af8db100ee0e3
--- /dev/null
+++ b/tools.py
@@ -0,0 +1,131 @@
+# tools.py
+
+import re
+import math
+from datetime import datetime
+import julian
+
+JULIAN = 33282
+
+def dateTime2julian(month, day, year, hour, minute, second):
+    
+    # initialize datetime object
+    dt = datetime
+        
+    # format date and time to  "May 09 2011 16:33:53"
+    dateTime = "%s/%s/%s %s:%s:%s" % (
+    day, month, year, hour, minute, second)
+
+    # dateTime conversion to "09/05/2011 16:33:53"
+    dateTime = "%s" % \
+        (dt.strptime(dateTime,
+        "%d/%b/%Y %H:%M:%S").strftime("%d/%m/%Y %H:%M:%S"))
+    
+    # conversion to "20110509163353"
+    epic_date = "%s" % \
+        (dt.strptime(dateTime,
+        "%d/%m/%Y %H:%M:%S").strftime("%Y%m%d%H%M%S"))
+
+    # conversion to julian day
+    julian = float((dt.strptime(dateTime, "%d/%m/%Y %H:%M:%S").strftime("%j"))) \
+           + ((float(hour) * 3600.) +
+             (float(minute) * 60.) + float(second)) / 86400.
+
+    # we use julian day with origine 0
+    julian -= 1
+    return julian
+
+def julian2dt(jd):
+    # see: https://en.wikipedia.org/wiki/Julian_day
+    # Julian Date	12h Jan 1, 4713 BC
+    # Modified JD	0h Nov 17, 1858	JD − 2400000.5
+    # CNES JD	0h Jan 1, 1950	JD − 2433282.5
+    jd = jd + JULIAN
+    dt = julian.from_jd(jd, fmt='mjd')
+    return dt
+
+def dt2julian(dt):
+    jd = julian.to_jd(dt, fmt='mjd')
+    jd = jd - JULIAN
+    return jd
+
+def dateTime2epic(month, day, year, hour, minute, second):
+    
+    # initialize datetime object
+    dt = datetime
+        
+    # format date and time to  "May 09 2011 16:33:53"
+    dateTime = "%s/%s/%s %s:%s:%s" % (
+    day, month, year, hour, minute, second)
+
+    # dateTime conversion to "09/05/2011 16:33:53"
+    dateTime = "%s" % \
+        (dt.strptime(dateTime,
+        "%d/%b/%Y %H:%M:%S").strftime("%d/%m/%Y %H:%M:%S"))
+    
+    # conversion to "20110509163353"
+    epic_date = "%s" % \
+        (dt.strptime(dateTime,
+        "%d/%m/%Y %H:%M:%S").strftime("%Y%m%d%H%M%S"))
+
+    return  epic_date
+
+
+
+
+# Dec2dmc convert decimal position to degree, mim with centieme string,
+# hemi = 0 for latitude, 1 for longitude
+def Dec2dmc(position, hemi):
+
+    if re.match('[EW]', hemi):
+        neg = 'W'
+        pos = 'E'
+    else:
+        neg = 'S'
+        pos = 'N'
+
+    if position < 0:
+        geo = neg
+    else:
+        geo = pos
+
+    # get integer and decimal part
+    dec, intg = math.modf(position)
+    dec = abs(dec)
+    intg = abs(intg)
+
+    if re.match('[EW]', hemi):
+        str = "{:0>3.0f}°{:0>7.4f} {}".format(intg, (dec / 100 ) * 6000, geo)
+    else:
+        str = "{:0>2.0f}°{:0>7.4f} {}".format(intg, (dec / 100 ) * 6000, geo)
+
+    return str
+
+# Dec2dms convert decimal position to degree, mim with second string,
+# hemi = 0 for latitude, 1 for longitude
+def Dec2dms(position, hemi):
+
+    if re.match('[EW]', hemi):
+        neg = 'W'
+        pos = 'E'
+    else:
+        neg = 'S'
+        pos = 'N'
+
+    if position < 0:
+        geo = neg
+    else:
+        geo = pos
+
+    # get integer and decimal part
+    dec, intg = math.modf(position)
+    
+    # get integer and decimal part of min.sec
+    sec, min = math.modf((dec / 100) * 6000)
+
+    if re.match('[EW]', hemi):
+        str = "{:0>3.0f}°{:2.4f} {}".format(intg, min + sec/100*60, geo)
+    else:
+        str = "{:0>2.0f}°{:2.4f} {}".format(intg, min + sec/100*60, geo)
+
+    return str