From 35017483cb2d02e4d59a1dec44c7ad459ad5b5ed Mon Sep 17 00:00:00 2001
From: Don Cross <cosinekitty@gmail.com>
Date: Sun, 23 Jun 2019 17:10:58 -0400
Subject: [PATCH] Fixed problem in Python MakeTime() function.y

---
 .gitignore                     |  1 +
 generate/template/astronomy.py | 18 +++++-------------
 generate/test.py               | 28 ++++++++++++++++++++++++++++
 generate/unit_test_python      | 10 ++++++++++
 source/python/astronomy.py     | 18 +++++-------------
 5 files changed, 49 insertions(+), 26 deletions(-)
 create mode 100644 generate/test.py
 create mode 100755 generate/unit_test_python

diff --git a/.gitignore b/.gitignore
index 722d5e71..9f94e5dd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 .vscode
+__pycache__
diff --git a/generate/template/astronomy.py b/generate/template/astronomy.py
index 3d25a289..ee703934 100644
--- a/generate/template/astronomy.py
+++ b/generate/template/astronomy.py
@@ -166,20 +166,12 @@ class astro_time_t:
 _EPOCH = datetime.datetime(2000, 1, 1, 12)
 
 def CurrentTime():
-    now = datetime.datetime.utcnow()
-    dt = now - _EPOCH
-    ut = dt.total_seconds() / 86400.0
+    ut = (datetime.datetime.utcnow() - _EPOCH).total_seconds() / 86400.0
     return astro_time_t(ut)
 
 def MakeTime(year, month, day, hour, minute, second):
-    # This formula is adapted from NOVAS C 3.1 function julian_date().
-    jd12h = (
-        day - 32075 + 1461 * (year + 4800
-        + (month - 14) / 12) / 4
-        + 367 * (month - 2 - (month - 14) / 12 * 12)
-        / 12 - 3 * ((year + 4900 + (month - 14) / 12)
-        / 100) / 4)
-    y2000 = jd12h - 2451545
-    ut = y2000 - 0.5 + (hour / 24.0) + (minute / (24.0 * 60.0)) + (second / (24.0 * 3600.0))
+    micro = round((second % 1) * 1000000)
+    second = math.floor(second - micro/1000000)
+    d = datetime.datetime(year, month, day, hour, minute, second, micro)
+    ut = (d - _EPOCH).total_seconds() / 86400
     return astro_time_t(ut)
-
diff --git a/generate/test.py b/generate/test.py
new file mode 100644
index 00000000..110ede36
--- /dev/null
+++ b/generate/test.py
@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+import sys
+sys.path.append('../source/python')
+import astronomy
+
+
+def Test_AstroTime():
+    expected_ut = 6910.270978506945
+    expected_tt = 6910.271779431480
+    time = astronomy.MakeTime(2018, 12, 2, 18, 30, 12.543)
+    diff = time.ut - expected_ut
+    if abs(diff) > 1.0e-12:
+        print('Test_AstroTime: excessive UT error {}'.format(diff))
+        sys.exit(1)
+
+    diff = time.tt - expected_tt
+    if abs(diff) > 1.0e-12:
+        print('Test_AstroTime: excessive TT error {}'.format(diff))
+        sys.exit(1)
+
+
+if len(sys.argv) == 2:
+    if sys.argv[1] == 'time':
+        Test_AstroTime()
+        sys.exit(0)
+
+print('test.py: Invalid command line arguments.')
+sys.exit(1)
diff --git a/generate/unit_test_python b/generate/unit_test_python
new file mode 100755
index 00000000..8b1f602e
--- /dev/null
+++ b/generate/unit_test_python
@@ -0,0 +1,10 @@
+#!/bin/bash
+Fail()
+{
+    echo "ERROR($0): $1"
+    exit 1
+}
+
+python3 --version || Fail "Cannot print python version"
+python3 test.py time || Fail "Failure reported by test.py"
+exit 0
diff --git a/source/python/astronomy.py b/source/python/astronomy.py
index 651cdcf8..5f624a69 100644
--- a/source/python/astronomy.py
+++ b/source/python/astronomy.py
@@ -257,20 +257,12 @@ class astro_time_t:
 _EPOCH = datetime.datetime(2000, 1, 1, 12)
 
 def CurrentTime():
-    now = datetime.datetime.utcnow()
-    dt = now - _EPOCH
-    ut = dt.total_seconds() / 86400.0
+    ut = (datetime.datetime.utcnow() - _EPOCH).total_seconds() / 86400.0
     return astro_time_t(ut)
 
 def MakeTime(year, month, day, hour, minute, second):
-    # This formula is adapted from NOVAS C 3.1 function julian_date().
-    jd12h = (
-        day - 32075 + 1461 * (year + 4800
-        + (month - 14) / 12) / 4
-        + 367 * (month - 2 - (month - 14) / 12 * 12)
-        / 12 - 3 * ((year + 4900 + (month - 14) / 12)
-        / 100) / 4)
-    y2000 = jd12h - 2451545
-    ut = y2000 - 0.5 + (hour / 24.0) + (minute / (24.0 * 60.0)) + (second / (24.0 * 3600.0))
+    micro = round((second % 1) * 1000000)
+    second = math.floor(second - micro/1000000)
+    d = datetime.datetime(year, month, day, hour, minute, second, micro)
+    ut = (d - _EPOCH).total_seconds() / 86400
     return astro_time_t(ut)
-