1 files changed, 29 insertions, 0 deletions
diff --git a/challenge-326/sgreen/python/ch-1.py b/challenge-326/sgreen/python/ch-1.py
new file mode 100755
index 0000000000..c05a79a942
--- /dev/null
+++ b/challenge-326/sgreen/python/ch-1.py
@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+
+from datetime import date
+import re
+import sys
+
+
+def day_of_year(input_date: str) -> int:
+    """
+    Calculate the day of the year from a date string in 'YYYY-MM-DD' format.
+    :param input_date: Date string in 'YYYY-MM-DD' format
+    :return: Day of the year as an integer
+    """
+
+    # Validate the input date format
+    if not re.match(r'^\d{4}-\d\d?-\d\d?$', input_date):
+        raise ValueError("Input date must be in 'YYYY-MM-DD' format")
+
+    year, month, day = map(int, input_date.split('-'))
+    return int((date(year, month, day).strftime('%j')))
+
+
+def main():
+    result = day_of_year(sys.argv[1])
+    print(result)
+
+
+if __name__ == '__main__':
+    main()