TimeSync

English | 简体中文

TimeSync is a Windows desktop app that shows Beijing Standard Time (UTC+08:00) beside the Windows clock and sets the system time immediately or on a schedule.

Version 1.0.0 · Published by LEC Software Studio / 乐程软件工作室

Run on Windows

Choose the package you received:

Package	How to launch
TimeSync-portable.zip	Extract the entire application folder, keeping its Qt runtime files together, then open TimeSync.exe.
TimeSync-static.exe	Place the single executable in your application folder and open it.

Use a folder protected from modification by unprivileged users: the executable runs with elevated permissions, including during scheduled synchronization.

Accept the Windows User Account Control (UAC) prompt at startup. Administrator access is required to adjust the system clock and manage the scheduled task.

Allow outbound UDP port 123 for NTP queries. TimeSync supports both IPv4 and IPv6 time servers.

The initial interface language is Simplified Chinese. Use the 界面语言 / Language selector to choose English or 简体中文. The window is titled Standard Time Sync in English and 标准时间同步 in Chinese.

Check and synchronize the clock

1. Read the Beijing Standard Time and Windows system time panels, with the clock difference displayed below them.
2. Select Refresh to request a new NTP sample while leaving the Windows clock unchanged.
3. Select Sync system time now to set the Windows clock using the verified standard time. TimeSync uses the current sample while it remains valid; otherwise, it queries NTP before setting the clock.

Open Edit servers to change the time sources and save the list. The defaults contain 25 servers from Aliyun, NIM, and CERNET.

NTP over UDP provides no cryptographic assurance of a server's authenticity. Sample verification includes origin-timestamp checks that associate replies with requests.

Set up automatic synchronization

1. In Automatic time sync, select Enable automatic time sync.
2. Enter a Sync interval between 1 and 10080 minutes; the default is 60 minutes.
3. Select Apply to create or update the Windows Task Scheduler task, then check Schedule status.

To delete the periodic task, select Remove schedule and confirm removal.

In the same Automatic time sync area, Sync once after sign-in at startup is a separate option, off by default. Select it to register a background synchronization task for the current user's sign-in, with a 30-second delay. Initial setup in the GUI still requires administrator authorization; subsequent sign-in runs do not display another UAC prompt. Clear the option to remove this task. It is independent of the periodic schedule and does not run before sign-in.

If the network is unavailable at sign-in, TimeSync retries time acquisition within a limited window. It does not retry the system-clock write.

Both tasks launch the same TimeSync executable used to configure them, under the current administrative user with highest privileges. Keep the executable and configuration file at their registered paths. If you move them, reopen the GUI from the new location and reapply the affected options.

Settings file

Use the GUI to change servers, scheduling, and language. Settings are stored in config.ini alongside the executable.

The sign-in sync option is read from Windows Task Scheduler, not stored in config.ini; the file retains the same three fields below.

The file format is UTF-8 with exactly three fields, one per line, without comments or section headers. This example uses three sample servers:

servers = ntp1.aliyun.com, ntp2.aliyun.com, ntp1.nim.ac.cn
scheduleIntervalMinutes = 60
language = zh-CN

Field	Accepted value
servers	Comma-separated NTP server list, managed through Edit servers.
scheduleIntervalMinutes	Integer from 1 to 10080, in minutes; defaults to 60.
language	zh-CN for Simplified Chinese (default) or en-US for English.

If config.ini is invalid, TimeSync keeps the file and reports an error. Edit it to match the format above, then retry.

Command-line use

Run these commands from the application folder; brackets indicate optional arguments:

TimeSync.exe
TimeSync.exe --sync-once [--dry-run] [--config <path>]
TimeSync.exe --install-task [--config <path>]
TimeSync.exe --remove-task [--config <path>]
TimeSync.exe --install-startup-task [--config <path>]
TimeSync.exe --remove-startup-task
TimeSync.exe --help

• Launching without arguments opens the GUI.
• --sync-once performs one synchronization; adding --dry-run fetches and prints an NTP sample while leaving the system clock unchanged.
• --install-task creates or updates the scheduled task using the configured interval.
• --remove-task deletes the scheduled task.
• --install-startup-task creates or updates the separate sign-in sync task for the current user, with a 30-second delay.
• --remove-startup-task deletes the sign-in sync task without changing the periodic schedule.
• --config <path> selects a configuration file for the operation.
• --help displays usage information.

Compile and package

Build requirements: Windows x64, Qt 6.9.1 MinGW 64-bit with Core, Network, and Widgets, MinGW-w64 with C++20 support, CMake 3.22+, and Ninja.

Run the commands from the source directory, replacing the angle-bracket placeholders with your Qt prefix and tool paths. The examples use shell-style \ line continuation; in PowerShell or Command Prompt, join each continued command onto one line and remove the trailing \ characters. Quote paths containing spaces.

Shared Qt application folder

cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_PREFIX_PATH=<shared-Qt-prefix> \
  -DCMAKE_CXX_COMPILER=<path-to-g++.exe> \
  -DCMAKE_MAKE_PROGRAM=<path-to-ninja.exe>
cmake --build build --parallel
ctest --test-dir build --output-on-failure
cmake --build build --target deploy-portable

When TimeSync is built against shared Qt, deploy-portable copies TimeSync.exe and the Qt runtime into build/deploy.

Static single executable

Use a separately built static Qt 6.9.1 qtbase installation containing the Windows platform plugin (QWindowsIntegrationPlugin) and Schannel TLS plugin (QSchannelBackendPlugin).

cmake -S . -B build-static -G Ninja -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_PREFIX_PATH=<static-Qt-prefix> \
  -DCMAKE_CXX_COMPILER=<path-to-g++.exe> \
  -DCMAKE_MAKE_PROGRAM=<path-to-ninja.exe>
cmake --build build-static --parallel

Resolve common problems

Problem	Action
All time sources fail to respond	Check outbound UDP port 123 access and review the configured servers in Edit servers.
Windows refuses a clock adjustment	Reopen the application and accept UAC. Ask an administrator to check the Change the system time user right in Local Security Policy.
Scheduled synchronization fails	Launch the application from its installed folder with administrator privileges and apply the schedule again.

Publisher and license

The About dialog identifies LEC Software Studio (乐程软件工作室) and links to the studio website and GitHub organization.

TimeSync is licensed under the GNU Affero General Public License v3.0.