Deadlines and Class Schedule System for LMS

Development of a Deadline and Schedule System for LMS

Deadlines and schedules form the temporal skeleton of a course. Without a proper system, students miss assignments, don't know when classes are, and instructors waste time on manual reminders.

Two Course Modes

Self-paced—students progress at their own pace. Deadlines are relative: "Assignment due 7 days after lesson start." No schedule.

Cohort-based—a cohort with fixed dates. Absolute deadlines and class schedules (webinars, seminars). Students enroll in specific cohorts.

Data Model

-- Cohorts
CREATE TABLE course_cohorts (
  id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  course_id       UUID REFERENCES courses(id),
  name            VARCHAR(200),           -- 'Cohort #5, March 2026'
  starts_at       DATE NOT NULL,
  ends_at         DATE,
  max_students    INT,
  enrollment_open BOOLEAN DEFAULT TRUE
);

-- Assignment deadlines
CREATE TABLE assignment_deadlines (
  id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  assignment_id   UUID REFERENCES assignments(id),
  cohort_id       UUID REFERENCES course_cohorts(id),
  -- Absolute deadline for cohort-based courses
  deadline_at     TIMESTAMPTZ,
  -- Relative for self-paced: N days from lesson start
  relative_days   INT,
  late_allowed    BOOLEAN DEFAULT FALSE,
  late_penalty_pct INT DEFAULT 0
);

-- Class schedule
CREATE TABLE schedule_events (
  id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  cohort_id       UUID REFERENCES course_cohorts(id),
  lesson_id       UUID REFERENCES lessons(id),
  title           VARCHAR(500),
  event_type      VARCHAR(50), -- 'webinar', 'seminar', 'qa_session'
  starts_at       TIMESTAMPTZ NOT NULL,
  ends_at         TIMESTAMPTZ NOT NULL,
  location_url    VARCHAR(2000),  -- Zoom/Meet link
  recording_url   VARCHAR(2000),  -- After event
  is_mandatory    BOOLEAN DEFAULT FALSE,
  timezone        VARCHAR(100) DEFAULT 'Europe/Moscow'
);

Calculating Personal Deadlines for Self-Paced

When a student enrolls in a course, all relative deadlines are converted to absolute deadlines and saved for that student:

async function assignDeadlines(studentId, courseId) {
  const enrollment = await db.enrollments.findOne({ studentId, courseId });
  const assignments = await db.assignments.findAll({ courseId });

  const deadlineRecords = assignments
    .filter(a => a.relativeDays !== null)
    .map(a => ({
      studentId,
      assignmentId: a.id,
      deadlineAt: addDays(enrollment.enrolledAt, a.relativeDays),
    }));

  await db.studentDeadlines.bulkCreate(deadlineRecords, {
    onConflict: 'ignore', // Don't overwrite on repeat call
  });
}

Display in Interface

For Students:

• Calendar with deadlines and classes
• "What to submit this week" list on dashboard
• Countdown timer for next deadline
• Categorization: overdue / today / this week / later

For Instructors:

• Cohort summary: how many submitted on time, how many didn't
• Bulk deadline extension for entire cohort

Deadline Notifications

Notifications sent via job queue on schedule:

// Cron job: runs every hour
async function sendDeadlineReminders() {
  const upcoming = await db.studentDeadlines.findAll({
    deadlineAt: {
      gte: new Date(),
      lte: addHours(new Date(), 25), // Next 25 hours
    },
    submittedAt: null, // Not yet submitted
    reminderSent24h: false,
  });

  for (const deadline of upcoming) {
    const hoursLeft = (deadline.deadlineAt - new Date()) / (1000 * 60 * 60);
    if (hoursLeft <= 24) {
      await sendReminderEmail(deadline.studentId, deadline.assignmentId);
      await db.studentDeadlines.update(deadline.id, { reminderSent24h: true });
    }
  }
}

iCal Export

Students want to see course schedules in Google Calendar or Apple Calendar:

import ical from 'ical-generator';

app.get('/api/courses/:id/schedule.ics', authMiddleware, async (req, res) => {
  const events = await db.scheduleEvents.findAll({ courseId: req.params.id });
  const calendar = ical({ name: course.title });

  events.forEach(event => {
    calendar.createEvent({
      start: event.startsAt,
      end: event.endsAt,
      summary: event.title,
      description: `Type: ${event.eventType}\nLink: ${event.locationUrl}`,
      url: event.locationUrl,
    });
  });

  res.setHeader('Content-Type', 'text/calendar');
  res.send(calendar.toString());
});

Timeline

Basic deadline system with notifications—4–5 days. Cohort-based schedule with calendar display and iCal export—another 4–5 days.