diff --git a/.github/workflows/swift-package-ci.yml b/.github/workflows/swift-package-ci.yml
index 0541d42..2a5e7b7 100644
--- a/.github/workflows/swift-package-ci.yml
+++ b/.github/workflows/swift-package-ci.yml
@@ -57,6 +57,10 @@ jobs:
           matrix = config['ci']
           if not matrix.get('include'):
               raise SystemExit('The CI matrix must have at least one entry')
+          for entry in matrix['include']:
+              timeout = entry.setdefault('timeout_minutes', 45)
+              if type(timeout) is not int or not 1 <= timeout <= 360:
+                  raise SystemExit('CI timeout_minutes must be an integer from 1 to 360')
           with open(os.environ['GITHUB_OUTPUT'], 'a') as output:
               print('matrix=' + json.dumps(matrix, separators=(',', ':')), file=output)
               print('command=' + config['check_command'], file=output)
@@ -67,7 +71,7 @@ jobs:
     needs: configure
     name: ${{ matrix.name }}
     runs-on: ${{ matrix.runner }}
-    timeout-minutes: 45
+    timeout-minutes: ${{ matrix.timeout_minutes }}
     strategy:
       fail-fast: false
       matrix: ${{ fromJSON(needs.configure.outputs.matrix) }}
diff --git a/Documentation/Reference/WorkflowIntegration.md b/Documentation/Reference/WorkflowIntegration.md
index b6831ac..ab89dfa 100644
--- a/Documentation/Reference/WorkflowIntegration.md
+++ b/Documentation/Reference/WorkflowIntegration.md
@@ -9,6 +9,9 @@ its bundle identifier selects the same compiler for `swift`, `xcrun` and
 `xcodebuild`. That Xcode still owns the Darwin SDK. Validate compiler and SDK compatibility together.
 Use a format-only entry with a consistent formatter toolchain, and compiler-check
 entries for each supported compiler. All entries must pass for acceptance.
+Each entry may set `timeout_minutes` to an integer from 1 to 360; omitted values
+use 45 minutes. The package owns this execution budget for its validation workload.
+Exceeding the budget fails the job and the aggregate validation result.
 
 `swift-package-ci.yml` accepts a configuration path and optional source ref. It
 checks out one commit, runs the declared matrix with read permissions, preserves
diff --git a/Tests/test_matrix.py b/Tests/test_matrix.py
new file mode 100644
index 0000000..9b60f5e
--- /dev/null
+++ b/Tests/test_matrix.py
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: Apache-2.0 WITH Swift-exception
+"""Exercise the reusable workflow's package-owned execution budgets."""
+
+import json
+import os
+from pathlib import Path
+import subprocess
+import sys
+import tempfile
+import textwrap
+import unittest
+
+ROOT = Path(__file__).resolve().parent.parent
+
+
+class MatrixTests(unittest.TestCase):
+    def setUp(self):
+        fixtures = ROOT / '.build/test-fixtures'
+        fixtures.mkdir(parents=True, exist_ok=True)
+        temporary = tempfile.TemporaryDirectory(dir=fixtures)
+        self.addCleanup(temporary.cleanup)
+        self.root = Path(temporary.name)
+        workflow = (ROOT / '.github/workflows/swift-package-ci.yml').read_text()
+        configure = workflow.split('- id: configuration', 1)[1]
+        self.program = textwrap.dedent(configure.split("python3 - <<'PY'\n", 1)[1].split('          PY\n', 1)[0])
+
+    def configure(self, entries):
+        configuration = self.root / 'release.json'
+        output = self.root / 'output'
+        output.write_text('')
+        configuration.write_text(json.dumps({'check_command': 'Scripts/check', 'ci': {'include': entries}}))
+        result = subprocess.run(
+            [sys.executable, '-c', self.program], cwd=ROOT, text=True,
+            capture_output=True,
+            env={**os.environ, 'CONFIGURATION': str(configuration), 'GITHUB_OUTPUT': str(output)},
+        )
+        values = dict(line.split('=', 1) for line in output.read_text().splitlines())
+        return result, values
+
+    def test_omitted_budget_and_per_entry_overrides(self):
+        entries = [
+            {'name': 'default', 'runner': 'ubuntu-24.04'},
+            {'name': 'long', 'runner': 'macos-26', 'timeout_minutes': 180},
+            {'name': 'short', 'runner': 'ubuntu-24.04', 'timeout_minutes': 1},
+            {'name': 'maximum', 'runner': 'ubuntu-24.04', 'timeout_minutes': 360},
+        ]
+        result, values = self.configure(entries)
+        self.assertEqual(result.returncode, 0, result.stderr)
+        matrix = json.loads(values['matrix'])['include']
+        self.assertEqual([entry['timeout_minutes'] for entry in matrix], [45, 180, 1, 360])
+        self.assertEqual([entry['name'] for entry in matrix], [entry['name'] for entry in entries])
+        self.assertEqual(values['command'], 'Scripts/check')
+
+    def test_invalid_budget_fails_before_emitting_runnable_matrix(self):
+        for timeout in (0, -1, 361, 1.5, '180', True, None):
+            with self.subTest(timeout=timeout):
+                result, values = self.configure([{'name': 'invalid', 'timeout_minutes': timeout}])
+                self.assertNotEqual(result.returncode, 0)
+                self.assertIn('timeout_minutes must be an integer from 1 to 360', result.stderr)
+                self.assertNotIn('matrix', values)
+
+
+if __name__ == '__main__':
+    unittest.main()