Class Schedule Builder with Clash Detection for Your Week

Use the free tool below: your data never leaves your browser — all work happens on your device, and nothing is uploaded to any server.

A class schedule is a clash detector first

Choosing classes feels simple until two required classes meet at the same time, or a timetable leaves a single lonely hour stranded between lectures. Students discover these problems after enrolment, when fixing them means queues, forms and full classes. A schedule builder catches the problems before enrolment. You enter each class with its day and times, and the tool shows the week as a table and flags every clash plainly, so you can swap a section while choices are still open.

The clash check is straightforward. Two classes clash when they share a day and their time ranges overlap. A class ending at 10:00 and another starting at 10:00 do not clash, because the first student can walk to the next room. A class from 09:00 to 10:30 and another from 10:00 to 11:00 do clash, even though the overlap is only thirty minutes, because you cannot be in two rooms at once. The builder applies that rule to every pair, so no clash hides behind a long list.

How to use the builder

List every class you plan to take, one per line, as Name, Day, Start, End. Use 24-hour times, such as 09:00 and 14:30.
Use the same day spelling for the same day every time. “Mon” and “Monday” look the same to you but not to the checker.
Build the schedule and read the clash report first, before admiring the table.
If a clash appears, try the other section of one class, or move an optional class to another day.
Check the gaps too. A three-hour gap between classes may be fine on campus, but a one-hour gap far from home is usually wasted.
Save or print the table once it is clash-free, and keep it for the first week, when rooms often change.

A worked example

Take three classes: maths on Monday 09:00 to 10:30, biology on Monday 10:00 to 11:00, and history on Tuesday 09:00 to 10:00. The builder flags maths and biology as a clash, because they overlap from 10:00 to 10:30 on Monday. History is fine. The fix might be moving biology to its Wednesday section, or choosing a later maths group. Without the check, the student would discover the clash in week one, when the Wednesday biology section is already full.

Now try a clean version: maths Monday 09:00 to 10:00, biology Monday 10:00 to 11:00, history Tuesday 09:00 to 10:00. The builder reports no clashes, because the back-to-back classes only touch at 10:00. That schedule is tight but workable, provided the two Monday rooms are close together, which is worth checking on a campus map before accepting it.

Tips for a schedule that survives week one

Leave ten minutes between back-to-back classes in different buildings. Timetables assume instant travel; campuses do not.
Put the hardest class at your best time of day. Morning people should not schedule calculus at 18:00 if a morning section exists.
Balance the days. Five classes on Monday and none on Friday feels efficient until Monday arrives.
Keep one free morning or afternoon per week for catch-up work, appointments and illness.
Check room locations, not just times. Two classes ten minutes apart in buildings a mile apart are a clash in practice.

Common mistakes

The most common mistake is entering times in 12-hour format without am or pm, so 02:00 means two in the morning to the checker. Use 24-hour times always. Another mistake is forgetting labs, tutorials and seminars, which are separate meetings of the same course and clash just as lectures do. A third mistake is building the schedule around favourite teachers instead of required classes. Required classes fill first, so secure them, then fit options around them.

Who uses a schedule builder

First-year students use it to make sense of their first enrolment. Returning students use it to compare section combinations quickly. Part-time students use it to fit classes around work shifts. Advisors use it to show students why a popular combination cannot work, with the clash visible instead of argued. Build the week before you enrol, and enrolment week becomes a confirmation, not a crisis.