Chochim guides
Things worth knowing before you hit the booking button.
- BOTHIs a second really 9.19 billion atomic ticks? How atomic clocks define time, and the 2030 redefinition9,192,631,770 caesium oscillations, fountain clocks, and the 2030 redefinition plan.
- BOTHThe day a minute had 61 seconds: why leap seconds stop in 2027The day clocks read 23:59:60, and why no leap seconds will be added from May 20, 2027.
- BOTHWhy does Korea share Japan's clock? The reason Seoul's true noon is around 12:30Korea sits near 127°E but its clocks follow 135°E. Four changes to standard time and Seoul's true noon.
- BOTHA watch whose second hand stops? How 'hacking' lets you set a watch to the second without the internetPull the crown and the seconds hand stops. How to sync a watch to standard time, plus radio and GPS watches.
- BOTHYour phone ignores a two-second error? How to sync your phone and PC clock to standard timeThe hidden rules of automatic time and how to sync each device to standard time.
- FOR KORDoes refreshing push you back in the queue? How sold-out tickets and online queues really workWhen cancelled seats come back and how a virtual queue keeps your place.
- BOTHHow Chochim measures server time: estimating milliseconds from a one-second Date header, and its limitsNarrowing one-second Date headers down to milliseconds, with a worked example and limits.
- FOR KORG-STAR 2026 tickets: 100% advance sales, 18,000 won adult, 8,000 won youth, Nov 19-22 at BEXCO BusanAdvance sales only, no on-site tickets. 18,000 won adult, Nov 19-22 at BEXCO.
- FOR KORFrozen The Musical Korea tickets: October 29 at 2 p.m., from Broadway to Charlotte TheaterGeneral booking Oct 29, 2 p.m. KST. The show, the cast, the theater and booking rules.
- FOR U.S.Stüssy release times: Friday 10 a.m. local, Korea time, and where to check official noticesRecent seasonal drops: Friday 10 a.m. local. U.S. and Korea time conversions.
- FOR KORKorea Grand Festival 2026: October 29 to November 15, K-Sale Festa and key benefitsOct 29 to Nov 15. K-Sale Festa, 70,000 lodging coupons, consumption lottery.
- FOR U.S.Supreme drop time: when the online shop updates, and how to read weekly drop trackersOfficial FAQ: shop updates at 11 a.m. New York time. Plus DST and drop trackers.
- FOR KORHyundai Card THE SIX tennis tickets: Naver sale opens October 27, who can book and the match scheduleNaver sale opens Oct 27. Naver Plus and Hyundai Card members only. Dec 25-27, Incheon.
- FOR KORKTX tickets now open 2 months ahead at 7 a.m.: the new booking window and how to catch returnsBooking now opens 2 months ahead at 7 a.m. Year-end timing and refund fees.
- FOR U.S.Daylight saving time ends Nov 1, 2026: what it does to drop times and the time gap with KoreaDST ends Nov 1. A 10 a.m. ET drop becomes midnight in Korea.
- FOR U.S.Black Friday and Cyber Monday 2026: dates and how to be ready when deals openBlack Friday Nov 27, Cyber Monday Nov 30. Start times and time zones.
- FOR U.S.Ticketmaster Verified Fan explained: registration, codes, the Waiting Room and time zonesRegistration, lottery codes, Waiting Room 30 min early, venue local time.
- FOR U.S.U.S. Nike SNKRS release times: 10 a.m. ET, Korea time, and how to prepareU.S. SNKRS drops at 10 a.m. ET; from November that's midnight in Korea.
- FOR KORAfter the 2027 CSAT (Suneung): every key date from scores to regular admissionSuneung Nov 19, scores Dec 11, regular applications Jan 4–7.
- FOR KORYear-end concert tickets: opening times, booking cutoffs and cancellation feesYear-end show season. Opening times, cutoffs and cancellation fees.
- FOR KORNOL Ticket (formerly Interpark Ticket): what changed and how to get readyInterpark Ticket is now NOL Ticket. Account switch and booking prep.
- FOR KOR2027 Seollal holiday dates and train ticket booking: when it opens and what to prepareSeollal 2027 runs Feb 6–9. When will train booking open?
- FOR KORNike SNKRS release times and Nike.com drop tips: getting ready for 10 a.m. Draws and LinesMost SNKRS drops land at 10 a.m. Draw vs. Line, and what to set up first.
- FOR KORTicket resale scams and how to avoid them: what to check before you pay, and how to reportFake escrow pages, endless "fee" requests, account-transfer tricks, and what to check before you pay.
- FOR KORWinning course registration: syncing to your school's server clock and using the course cartSync to your school's server clock, use the course cart well, and what to do when a class fills up.
- FOR KORGetting Korean Series tickets: from the day before to game dayWhich games are where, "if necessary" games, day-of returns and the tougher scalping law.
- BOTHWhat is server time, and why is it different from your clock?Sales open on the seller's clock, not yours. Why they drift apart and how we measure it.
- FOR KORConcert ticketing in Korea: from the day before to paymentPrep the day before, when exactly to click, queues, seat picks, payment and returns.
- FOR KORHoliday train tickets in Korea: booking KTX for Seollal and ChuseokHow Korail's holiday booking works, what to set up early, payment deadlines and returns.
- BOTHHow fast are human reactions? Averages, measurement and getting fasterThe 0.2-second average, the 0.1-second false-start rule, and why online tests read slow.