diff --git a/CHANGELOG.md b/CHANGELOG.md
index bf56841..69d2919 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -38,6 +38,7 @@ uses: qBraid/upload-course-action@v0.1.0-beta
 
 ### Added
 - Unit tests for JSend response handling in course creation and polling
+- Forward the optional `durationWeeks` field (author-declared course length in weeks, integer 1-52) from `course.json` to the deploy payload; previously the validate step's model round-trip silently dropped it. An out-of-range or non-integer value (including a numeric string such as `"3"`) now fails validation with a clear message, and an absent field serializes as `null`, which the qBraid API treats as not declared
 - Unit tests for shared deploy payload/response handling in `deploy_common.py`
 - Action inputs to configure polling limits (`max-poll-attempts`, `poll-interval-seconds`, `max-consecutive-errors`)
 - Comprehensive pytest testing infrastructure with unit and E2E tests
diff --git a/src/scripts/validate_course.py b/src/scripts/validate_course.py
index 439eeea..f03f336 100644
--- a/src/scripts/validate_course.py
+++ b/src/scripts/validate_course.py
@@ -112,6 +112,11 @@ class Course(BaseModel):
     tags: List[str]
     content: List[Chapter]
     deployedTo: List[str] = Field(..., min_length=1)
+    # Author-declared course length in weeks, forwarded to the qBraid API,
+    # which enforces the same 1-52 integer range. Optional: courses without
+    # it keep the platform's chapter-count estimate. strict, because pydantic
+    # would otherwise coerce "3" to 3 and forward a value the API rejects.
+    durationWeeks: Optional[int] = Field(None, ge=1, le=52, strict=True)
 
     @field_validator("deployedTo")
     @classmethod
@@ -192,7 +197,9 @@ def validate(self) -> None:
 
         logger.info("✅ course.json structure and file sizes are valid")
 
-        # Save course data for next steps
+        # Save course data for next steps. A course.json without
+        # durationWeeks serializes it as null; the qBraid API treats null
+        # the same as an absent field.
         try:
             with open(Config.COURSE_DATA_FILE_NAME, "w") as f:
                 json.dump(course.model_dump(mode="json"), f)
diff --git a/test/unit/test_validate_course.py b/test/unit/test_validate_course.py
index 37f3670..f83bfc8 100644
--- a/test/unit/test_validate_course.py
+++ b/test/unit/test_validate_course.py
@@ -2,6 +2,7 @@
 from unittest import mock
 
 import pytest
+from pydantic import ValidationError
 from validate_course import (
     Course,
     CourseValidator,
@@ -172,6 +173,41 @@ def test_format_missing_kernel_error_limits_kernel_sample(self):
         assert message.count("kernel_") <= 10
         assert "..." in message
 
+    def _duration_course_data(self, **extra):
+        data = {
+            "courseName": "Test Course",
+            "courseDescription": "Desc",
+            "visibility": "public",
+            "imageLink": {"darkLogo": "d.png", "lightLogo": "l.png"},
+            "tags": ["tag"],
+            "content": [],
+            "deployedTo": ["qbraid.com"],
+        }
+        data.update(extra)
+        return data
+
+    def test_duration_weeks_is_forwarded_in_payload(self):
+        """A declared durationWeeks must survive into the deploy payload."""
+        course = Course(**self._duration_course_data(durationWeeks=2))
+
+        payload = course.model_dump(mode="json")
+
+        assert payload["durationWeeks"] == 2
+
+    def test_absent_duration_weeks_serializes_as_null(self):
+        """No durationWeeks in course.json -> null in the payload, which the
+        qBraid API treats the same as an absent field."""
+        course = Course(**self._duration_course_data())
+
+        payload = course.model_dump(mode="json")
+
+        assert payload["durationWeeks"] is None
+
+    @pytest.mark.parametrize("bad_value", [0, -3, 53, 2.5, "two", "3", True])
+    def test_out_of_range_duration_weeks_fails_validation(self, bad_value):
+        with pytest.raises(ValidationError):
+            Course(**self._duration_course_data(durationWeeks=bad_value))
+
     @mock.patch("builtins.open", new_callable=mock.mock_open)
     @mock.patch("json.load")
     @mock.patch("validate_course.Path.exists")