Understanding the time zone configuration in windows (Time Service in Windows Part 2)
Difference between time
Before describing the time zone configuration you should know what is time zone and how and why it’s used, relation between time and time zone, and difference between time
Due to time difference between the countries, like time in UK is not the same in US, to differentiate the time between the different parts of the world we use the time zone, I call it difference between time
Computers and servers store time in Coordinated Universal Time (UTC), when viewed through any application (or) viewing system time it’s displayed according to the local time zone of the computer, UTC is equal to GMT
Current system time (UTC) + Time zone (UTC +5.30) = Display time
5 + 5.30 = 10.30
So on core all the systems are uses UTC time, while displaying the system time it will be converted according to the time zone configuration
The W32Time service starts automatically on computers that are joined to a domain. For computers that are not joined to a domain, you can start the time service manually.
On computers that are joined to a domain, time synchronization takes place when the W32Time service turns on during system startup. The Net Logon service looks for a domain controller that can authenticate and synchronize time with the client. When a domain controller is found, the client sends a request for time and waits for a reply from the domain controller. This communication is an exchange of SNTP packets intended to calculate the time offset and roundtrip delay between the two computers.
Time passed to any client in the domain is unadjusted UTC time, which is adjusted to local time based on the time zone configuration of the workstation. Adjusting the time on the domain controllers will not change the time for the workstations. They have to be updated with the new time zone information as well,
Time zone information will not sync to client from Domain controller, we have to do the time zone change manually, for bulk change we can users the Microsoft hot fix
W32Time uses coordinated universal time (UTC), which is based on an atomic time scale and is the correct term to use when talking about time and time synchronization. UTC is the name for time that is independent of time zone. Time zone information is stored in the computer’s registry and is added to the system time just before it is displayed to the user.
How to change time zone configuration in windows
In Control Panel -> Date/Time -> Time Zone
The process to change the DST is as follows:
Or Use the utility TZEDIT.EXE
– Select you time zone, Select the Time Zone
Note: For the updated TZ to take effect without rebooting the server