In a dual boot environment, where you have both Windows and a Linux distribution such as Ubuntu installed on your machine, you may encounter issues with the system clock time. This typically happens because Windows and Linux handle the system clock differently. Windows treats the system clock as local time, while Linux treats it as Coordinated Universal Time (UTC). This discrepancy can lead to confusion and potential issues when you switch between the two operating systems. This article will guide you through several methods to resolve this issue.
To fix dual boot clock time issues, you can either make Windows use UTC for the system clock or configure Ubuntu to treat the system clock as local time. Additionally, you can use the timedatectl command in systemd-based Ubuntu versions to change the hardware clock time standard. If the issue persists, you can try changing the time zone in Ubuntu to align it with the BIOS time.
Understanding the Problem
Before we dive into the solutions, it’s important to understand the problem. In a dual boot system, Windows assumes the system clock is set to the local time zone of the user and adjusts it accordingly. On the other hand, Linux, including distributions like Ubuntu, assumes the system clock is set to UTC and adjusts the displayed time based on the user’s time zone setting.
This difference in approach can result in an incorrect time display when you switch between the two operating systems. For example, if you set the correct time in Windows, then reboot into Linux, the time might be off by several hours, depending on your time zone.
Solution 1: Make Windows Use UTC
One way to resolve this issue is to make Windows use UTC for the system clock, just like Linux. This can be achieved by creating a registry file in Windows.
In Windows, open Notepad and paste the following lines:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation]
"RealTimeIsUniversal"=dword:00000001Save this file with a .reg extension, then double-click the file to merge it into the Windows Registry. This tells Windows to treat the system clock as UTC, not local time.
Solution 2: Make Ubuntu Use Local Time
Alternatively, you can configure Ubuntu to treat the system clock as local time, similar to Windows. To do this, open a terminal in Ubuntu and type the following command:
sudo nano /etc/default/rcSThis command opens the rcS file in a text editor called nano. In this file, find the line that says UTC=yes and change it to UTC=no. Save and close the file. Now, Ubuntu will treat the system clock as local time.
Solution 3: Set the Hardware Clock to Local Time in Systemd-based Ubuntu
If you are using a systemd-based version of Ubuntu (15.04 and above), you can use the timedatectl command to change the hardware clock time standard.
To set the hardware clock to local time, use the following command:
timedatectl set-local-rtc 1 --adjust-system-clockTo revert it back to UTC, use:
timedatectl set-local-rtc 0 --adjust-system-clockThe set-local-rtc parameter sets the system real-time clock (RTC), and the --adjust-system-clock parameter tells Ubuntu to update the system clock from the RTC.
Solution 4: Change the Time Zone in Ubuntu
If the issue persists, you might consider changing the time zone in Ubuntu to a location that uses UTC+0. This can align the Ubuntu time with the BIOS time.
To change the time zone in Ubuntu, use the following command:
sudo dpkg-reconfigure tzdataThis command launches a graphical interface that allows you to select your desired time zone.
Conclusion
In a dual boot system, clock time issues can be a common problem due to the different ways Windows and Linux handle the system clock. By adjusting the settings in either operating system, you can ensure that the correct time is displayed, regardless of which OS you’re currently using. Always remember to back up your system before making any changes to the system configuration or registry files.
A dual boot environment refers to a setup where two different operating systems, such as Windows and Linux, are installed on the same computer, allowing the user to choose which operating system to boot into when starting up the machine.
The system clock time differs in a dual boot environment because Windows treats the system clock as local time, while Linux treats it as Coordinated Universal Time (UTC). This difference in approach can lead to time discrepancies when switching between the two operating systems.
To make Windows use UTC for the system clock, you can create a registry file by following the steps provided in Solution 1 of the article. This file tells Windows to treat the system clock as UTC, aligning it with Linux.
Yes, you can configure Ubuntu to treat the system clock as local time, similar to Windows. Solution 2 in the article provides the steps to do this by editing the rcS file in Ubuntu.
If you are using a systemd-based version of Ubuntu (15.04 and above), you can use the timedatectl command to change the hardware clock time standard. Solution 3 in the article explains how to set the hardware clock to either local time or UTC.
If the issue persists, you can consider changing the time zone in Ubuntu to align it with the BIOS time. Solution 4 in the article provides the steps to change the time zone using the dpkg-reconfigure tzdata command.
Yes, it is always recommended to back up your system before making any changes to the system configuration or registry files. This ensures that you have a copy of your data in case anything goes wrong during the process.
