feat(day 170): determine odd or even day from Unix timestamp

Author: JohnSunny21

FreeCodeCamp/CodingQ/OddOrEvenDay.py

@@ -0,0 +1,81 @@
+"""   
+
+Odd or Even Day
+Given a timestamp (number of milliseconds since the Unix epoch), return:
+
+"odd" if the day of the month for that timestamp is odd.
+"even" if the day of the month for that timestamp is even.
+For example, given 1769472000000, a timestamp for January 27th, 2026, return "odd" because the day number (27) is an odd number.
+"""
+
+import unittest
+
+
+class OddOrEvenDayTest(unittest.TestCase):
+
+    def test1(self):
+        self.assertEqual(odd_or_even_day(1769472000000), "odd")
+        
+    def test2(self):
+        self.assertEqual(odd_or_even_day(1769444440000), "even")
+
+    def test3(self):
+        self.assertEqual(odd_or_even_day(6739456780000), "odd")
+
+    def test4(self):
+        self.assertEqual(odd_or_even_day(1), "odd")
+
+    def test5(self):
+        self.assertEqual(odd_or_even_day(86400000), "even")
+
+
+
+
+
+from datetime import datetime
+def odd_or_even_day(timestamp):
+
+    seconds = timestamp / 1000.0
+    date_obj = datetime.fromtimestamp(seconds)
+
+    if date_obj.day % 2 == 0:
+        return "even"
+    else:
+        return "odd"
+    
+"""
+
+1. Timezone awareness
+=> datetime.fromtimestamp() uses the localtimezon of the system.
+-> if you want consistent results regradless of environment, use datetime,utcfromtimestamp()
+
+-> otherwise your function may return different results depending on where it runs.
+"""
+
+def odd_or_even_day(timestamp):
+
+    dt = datetime.utcfromtimestamp(timestamp / 1000)
+    
+    day = dt.day
+
+    return "odd" if day % 2 else "even"
+
+"""
+=> Use UTC consistently to avoid timezone shifts.
+-> datetime.utcfromtimestamp() in Python
+-> Parity check is just day % 2
+"""
+def odd_or_even_day(timestamp):
+
+    return "even" if datetime.utcfromtimestamp(timestamp / 1000).day%2 == 0 else "odd"
+
+
+odd_or_even_day = lambda ts: "even" if datetime.utcfromtimestamp(ts / 1000).day % 2==0 else "odd"
+
+
+
+if __name__ == "__main__":
+
+    unittest.main()
+
+