July 23, 2025

Automatically deduct late penalties in CodeGrade

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Learn how to set up automatic penalties for late submissions in CodeGrade, making your grading more transparent and efficient.

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Late submissions are a reality in most courses, and manually applying penalties can be tedious and inconsistent. With CodeGrade AutoTest, you can fully automate late point deductions using a small script and the built-in rubric system.

This guide walks you through setting up a penalty system that deducts 1 point per day late, up to a maximum of 10 points.

How It Works

Each submission in CodeGrade includes:

submitted_at: When the student submitted the work.
deadline: The assigned due date (automatically stored per assignment or per student).

Using this metadata, we’ll:

Compare the submission time to the deadline.
Calculate how many full days late the submission was.
Deduct 1 point per day late.
Apply that deduction to the rubric via AutoTest.

Step 1: Create a Rubric Category

Go to your assignment settings > Rubric and create a continuous rubric category to handle late penalties:

Name: Late Penalty
Minimum Points: -10
Maximum Points: 0

This allows up to 10 points to be deducted automatically, without any manual grading required.

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Step 2: Add a Hidden Custom Test Block

Now go to the AutoTest Test, and follow these steps:

1. Add a Connect Rubric Block

Link it to the Late Penalty rubric category you created.

2. Inside it, add a Hide Config Block

This prevents students from seeing the test script output or logic.

3. Inside that, add a Custom Test Block

Use the script below to calculate the late penalty and output it in a format CodeGrade Custom Test understands.

Script

#!/bin/bash

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python3 <<EOF

import os

import json

import math

from datetime import datetime, timedelta

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ONE_DAY = timedelta(days=1)

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# Load submission info

cg_info = json.loads(os.environ["CG_INFO"])

submitted_at = datetime.fromisoformat(cg_info["submitted_at"].replace("Z", "+00:00"))

deadline = datetime.fromisoformat(cg_info["deadline"].replace("Z", "+00:00"))

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# Calculate how many days late

days_late = math.ceil((submitted_at - deadline) / ONE_DAY)

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# Determine score

if days_late <= 0:

print("Submitted on time")

print('{ "tag": "points", "points": "1" }', file=open(3, "w"))

elif days_late <= 10:

print(f"{days_late} day(s) late")

score = 1 - days_late / 10

print(f'{{ "tag": "points", "points": "{score}" }}', file=open(3, "w"))

else:

print("Very late, maximum penalty")

print('{ "tag": "points", "points": "0" }', file=open(3, "w"))

EOF

This setup ensures that late penalties are applied automatically, fairly, and invisibly, saving time for instructors and ensuring consistency for students.

You can use this configuration as a starting point and customize it to match your course policies. For example: