Winning course registration: syncing to your school's server clock and using the course cart

Chochim editorial team · October 19, 2026

Whether you get the timetable you want shapes your whole semester. Popular electives and required major courses can fill within seconds, so registration day feels a lot like concert ticketing. The principle is the same too: the registration button opens on the school's server clock, not your computer's.

1. Check your school's server time

Chochim can measure sites that aren't on our list if you type in the address.

1. From your school's registration site address, copy just the domain, without https:// or the path after it. It looks something like sugang.○○.ac.kr.
2. Paste it into the "Site address" field on Chochim's home page and press Measure server time.
3. Check the server time and margin of error shown. If the margin is large, measure again.

Some schools put security equipment or a queue service in front, so measurement may fail or show a different value from the real registration server. In that case, use the reading as a reference only. Why server time differs is explained in What is server time?

2. Use the course cart properly

Many schools have a course cart or wish list period before registration proper. What this step does varies by school.

• If it only works as a list: on registration day you can register straight from the cart with one button, saving the time it takes to type course codes.
• If it registers you automatically when within capacity: if fewer people put a course in their cart than it has seats, everyone is confirmed; if more, the course is contested in regular registration.

Check your school's academic notice to see which method it uses. Your strategy changes completely depending on the answer.

3. Decide your order

• Start with the courses that fill fastest: popular electives, small major courses and courses you need to graduate go first.
• Prepare backups: write down a substitute course in the same time slot to register right away if your first choice fills.
• Check for time conflicts: make sure your backups don't clash with other courses so you don't lose time to error messages.

4. On registration day

• Log in ahead: some schools time out logins quickly, so log in again a few minutes before it starts.
• Stable connection: use a wired line or stable Wi-Fi if you can, and close other programs.
• Click in time with the server's top of the hour: click too early and you'll get a "registration is not open" message and lose time. Clicking 0.1–0.3 seconds after the server's top of the hour is safer. Put the start time into Chochim's opening countdown to see the time left by the server clock.
• Don't refresh if a queue appears: refreshing after you get a queue number can push you back.
• Never use macros: most schools ban automated registration programs, and getting caught can mean cancelled registration or discipline.

5. If you miss out

• Add/drop period: there's a course change period around the start of term. Seats open up as other students switch courses.
• Watch for open seats: seats free up often when many students drop courses. Some schools release open seats at set times, so check the notice.
• Ask for more seats: if you need the course to graduate, ask the department office whether extra seats or an added section are possible.

Checklist

Measure your school's server time →