Second-Sync: PiP, Server time.

Accurate server time, at a glance.

"Second-Sync" is a time sync tool designed for moments where every second counts—like course registration or ticketing—by multi-sampling HTTP Date from your desired site and adjusting the error with the server clock down to the millisecond. It maintains accuracy over time through drift tracking, and its PiP timer ensures you never miss real-time server time even while using other apps.

Key Features
- Precision Synchronization: Collects HTTP Date in parallel at least 30 times, then calculates offset after RTT correction, outlier removal, and EMA smoothing.
- Drift Estimation: Performs linear regression on measured samples to track device clock drift, maintaining accuracy over time.
- Picture-in-Picture Timer: Display a PiP timer as a sub-app to monitor server time in real-time while using browsers or other apps.
- Quick Access to Example Sites: Provides shortcut buttons to instantly load major Korean university course registration pages and ticket booking sites.
- Multilingual Support: Supports Korean, English, Japanese, and Simplified Chinese. Language settings can be configured separately within the app.

Recommended For
- Those needing server time in situations where it's critical, such as course registration, ticketing, or reservations.
- Those wanting to view accurate server time on their iPhone or iPad while making reservations outside.

Important Notes
- Synchronization may fail on sites that do not support the HTTP Date header. In such cases, please enter a different synchronization server or use the example sites provided within the app.
- Picture in Picture functionality only works on supported devices (iOS 15 or later, including iPadOS).
- Synchronize your server time with pinpoint accuracy right now. With just one button press, enjoy stable synchronization and a PiP timer—don't miss a crucial moment!