Precise server time, at a glance.
Second-Sync is a time synchronisation tool for moments where one second matters, such as course enrolment and ticketing. It multi-samples the HTTP Date of your chosen site and aligns the difference from the server clock down to milliseconds. Drift tracking maintains accuracy over time, while the PiP timer lets you watch live server time even when using other apps.
Key features
- Precise synchronisation: collects HTTP Date in parallel at least 30 times, then calculates the offset after RTT compensation, outlier removal and EMA smoothing.
- Drift estimation: runs linear regression on measured samples to track the slope of the device clock and maintain accuracy as time passes.
- PiP timer: opens a Picture in Picture timer as a companion app, so you can monitor the server clock live while using a browser or other apps.
- Example site shortcuts: quick buttons to load course enrolment pages for major Korean universities and ticket booking sites.
- Multilingual support: supports Korean, English, Japanese and Simplified Chinese, with a separate in-app language setting.
Recommended for
- Anyone who wants exact server time in situations where it is critical, such as enrolment, ticketing or reservations.
- Anyone who wants to keep accurate server time visible on iPhone or iPad while booking on the go.
Notes
- Synchronisation may fail on sites that do not support the HTTP Date header. If so, enter another target server or use the example sites in the app.
- Picture in Picture works only on supported devices running iOS 15 or later, including iPadOS.
- Sync your server time with Second-Sync now. One button gives you stable synchronisation and a PiP timer, so you do not miss the important moment!
Ratings & Reviews
This app has not received enough ratings or reviews to display an overview.
• New illustrated how-to guide
• Improved schedule screens
• Popup button moved right under the clock
• Naver Form added to ticketing sites
• Stability improvements
Version 1.5.6
The developer, Minjun Kim, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
Purchases
Location
Identifiers
Usage Data
Diagnostics
Other Data
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
Diagnostics
Privacy practices may vary based, for example, on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
