What Is a Time Zone?
When we visit a website, the website first obtains your IP address. Every IP address corresponds to a geographic location—including country, state/province, city, and even latitude and longitude information. Each country or region has its corresponding time zone. Some countries with large land areas span multiple time zones; for example, Russia has 11 time zones, while the United States and its territories cover 9 time zones.
Websites can map your IP address to an actual geographic location through online services or IP databases. Once the geographic location is obtained, the website can further determine the time zone of that location.
Two Types of “Time”: IP Local Time and System Time
Websites can obtain time-related information in two ways:
First: IP-Based Local Time
After determining your geographic location based on your IP address, the website combines the server time with the UTC offset to calculate the local time corresponding to that location. This is the time “inferred” by the website, and it depends on the IP address you are currently using.
Second: JavaScript-Based System Time
When you visit a website, the website can run JavaScript code in your browser to directly read the system time on your computer (or phone). This is the time set on your device itself.
Websites typically obtain a user’s system time for the following purposes:
User experience: News websites push the latest information based on the user’s time, and e-commerce websites display different promotional campaigns based on the user’s time.
Security considerations: Checking whether there is a significant difference between the user’s system time and the IP address time to determine whether the device has been tampered with, or whether the user is using a VPN or proxy server.
Data analysis: Understanding when users are most active, or analyzing user behavior patterns during different time periods.
Content management: Correctly displaying the publication time of posts on blogs or forums.
Risks of Time Inconsistency
Some website platforms compare the two types of “time” mentioned above—that is, IP-based local time and system time obtained through JavaScript. If the two are inconsistent, or if the difference is too large, the website system may mark your account as suspicious, or even ban it directly.
Website operators usually believe that a real user’s system time should not deviate significantly from the time of the IP location. Such inconsistency may indicate that:
·The user’s device time has been maliciously tampered with
·The user is accessing the website using a VPN or proxy server
·The account may have been compromised by hackers
All of the above situations may violate the website’s user agreement. Therefore, when a website bans an account, it often requires the user to provide relevant evidence to prove account ownership. This is why some users are detected by websites when they use a VPN or proxy if the “time issue” is not handled properly.
In practice, websites can obtain your time zone information through two channels: first, by matching your IP address in an IP database; second, by reading it from the operating system’s regional settings through the browser’s API. The website checks whether the two are consistent. If they are not, it may assume that you are using a proxy server located in another time zone.
Time zone information is an important component of browser fingerprinting. When used together with information such as IP address, it can improve the accuracy of user identification.
How to Prevent Time-Related Fingerprint Tracking?
To avoid triggering website risk control due to time inconsistency, the core principle is to ensure that the IP-based time zone and the system time zone remain consistent.
1. Change the System Time Zone
You can manually adjust your device’s system time zone to match the time zone of the location corresponding to your current IP address. However, this method affects the time display of all software on the device, and some advanced scripts may still detect the real time zone through methods such as the Performance API.
2. Use Browser Extensions
Some browser extensions can modify the time zone information exposed by the browser to web pages. You can manually specify a time zone, or allow the extension to automatically detect and match the time zone based on the IP address. However, such plugins may be identified by some platforms as automation tools.
3. Use Tools with Time Zone Synchronization Features (Recommended)
A more ideal solution is to use professional tools that can automatically synchronize the IP and time zone. Such tools can usually automatically calculate and apply a matching time zone to the browser environment based on the proxy IP you configure when creating a new environment. In this way, parameters such as time zone, language, and screen resolution can be ensured to fully match the IP location. Most importantly, ensuring that the system time zone obtained by JavaScript remains consistent with the proxy location’s time zone is crucial for protecting your account security.
4. Maintain Consistency Across Multiple Dimensions
In addition to time zone, information such as language and keyboard layout may also be associated with geographic location. For better protection, it is recommended to ensure that this information remains logically consistent with your IP location.