Registration opens at some unreasonable hour, you have eleven minutes to pick your courses, and the timetable you built in your head said MATH was Mondays at nine. Then you notice BIO is also Monday at ten, and you do not have the whole week in front of you to work out what else it touches.
This checks that for you. Add every course with its day and start and end time, press Check Conflicts, and it reports which pairs overlap, by exactly how many minutes, and where.
One honest detail: the overlap window is printed to the minute, so you will see “Overlap: 10:00-10:20” rather than a vague warning. A twenty-minute clash and a two-hour clash look very different when you are deciding whether to fight for a different section.
Add your courses with days and times to check for schedule conflicts and get suggestions to fix them.
How to use it
Fill in course name, day, start time and end time, then press Add Course. Each one drops into a list under the form with a Remove button beside it, so you can take out a course you added by mistake without starting over.
Once there are at least two courses in the list, press Check Conflicts. With fewer than two it tells you so rather than returning a tidy empty result. Two other messages you might see: “Please fill in all fields.” if a name or a time is blank, and “End time must be after start time.” if a course is entered backwards.
If nothing overlaps you get “No conflicts found! Your schedule is clear.” Reset empties the list and the result box at the same time.
A worked timetable
Four courses, three of them on a Monday morning that has gone badly:
| Course | Day | Start | End |
|---|---|---|---|
| MATH 101 | Monday | 09:00 | 10:20 |
| BIO 110 | Monday | 10:00 | 11:50 |
| CHEM 130 | Monday | 10:00 | 12:50 |
| ENGL 200 | Wednesday | 13:00 | 14:30 |
Press Check Conflicts and the heading reads Conflicts Found: 3. The three are MATH 101 against BIO 110 (10:00-10:20), MATH 101 against CHEM 130 (10:00-10:20), and BIO 110 against CHEM 130 (10:00-11:50). ENGL 200 on Wednesday afternoon touches nothing.
Three sounds alarming until you notice it is a count of pairs, not a count of broken courses. Those three conflicts are one problem: two labs stacked on top of a lecture in the same two hours. The suggestion under each one names the second course in the pair and tells you to move it, which in this case is advice you would give yourself anyway.
Move CHEM 130 to a Tuesday section of the same time and the report drops to Conflicts Found: 1, which is the MATH and BIO pair left over from the morning. That single number is the useful part of this tool: it tells you whether the fix you just found actually cleared the timetable, or whether you have shuffled the problem to a different day.
The rules it uses
Two courses clash only if they are on the same day and their times cross. The test is strict, which means a class ending at 10:20 and another starting at 10:20 do not clash — the tool calls that clear, and technically it is.
Practically it is a different question. A zero-minute gap between a lecture in one building and a lab in another is a real problem the tool will happily wave through, because it has no idea how big your campus is. Check the tight ones yourself: anything under fifteen minutes between buildings is a gamble, and a first-year timetable is where people learn that.
Multi-day courses need one row each. A Monday/Wednesday/Fri 9am class is three separate entries, and forgetting that is the most common way to miss a clash. The same applies to labs with a separate discussion section.
What it does not look at: rooms, instructors, prerequisites, your commute, or whether you were hoping for a Friday off. And nothing is saved — refresh and the list is empty, so write down the schedule you settled on.
Other tools
- course retake GPA — what repeating a course does to the average you are protecting
- course retake impact — the longer version of the same decision
- cross contamination guide — the kitchen version of the same rule, keeping two things apart that must not share a space
Frequently asked questions
What exactly counts as a conflict?
Two courses on the same day whose times overlap. Touching times do not count: 09:00-10:20 and 10:20-11:50 are treated as clear, because the first ends exactly when the second begins.
How do I enter a Monday, Wednesday and Friday class?
Three rows, one for each day, with the same times. The tool works on a single day at a time, so a three-day course is three entries in the list.
Why does it report three conflicts when I can only see one clash?
It counts pairs of courses, not problems. Three courses all overlapping on Monday morning produce three pairs: A with B, A with C, B with C. One scheduling mistake, three lines in the report.
Does it allow for walking between buildings?
No. It only compares clock times, so a back-to-back pair in different buildings comes back clear. If you know the walk is ten minutes, treat any gap under fifteen as a clash yourself.
Does it check prerequisites or saved timetables?
No. Time overlap is the whole test, and nothing is stored after you leave the page. Course requirements come from the calendar or your department, and the final timetable is worth a screenshot once you are happy with it.