Add, remove and change time zones. How to change UTC time zone and get actual time

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One of the functions of a computer is an electronic clock. With this watch operating system Windows can get accurate information about the current time and date. This digital clock works quite accurately. Even if you completely turn off the computer and turn off the power to the system unit, the clock will not go wrong, and the next time you turn it on it will show right time.

For correct operation It is very important for your computer to have this clock show the correct time because time information is provided when files are created, is used to encrypt data, and is also used to perform other computer functions.

The need to change the date in Windows 7 does not arise often. For example, such a need may arise after disconnecting the battery from motherboard. In this article we will talk about how to change the date in Windows 7.

In fact, changing the date in Windows 7 is very simple. To do this, left-click on the system clock, which is located in the lower right corner of your screen.

After this, a pop-up window with a clock and calendar will appear in front of you.

In order to change the date in Windows 7, you need to click on the “Change date and time settings” link.

After this, a small window called “Date and Time” will open in front of you.

It should be noted that the “Date and time” window can be opened through the Control Panel. To do this, open the Control Panel and go to the “Clock, language and region” section, and then to the “Date and Time” subsection.

In the “Date and Time” window, you need to click on the “Change Date and Time” button.

After this, a window called “Setting time and date” will appear. Here you can change the date in Windows 7. To do this, click on the calendar title. In our case, this is “August 2014”.

Once clicked, the current year will appear in the title bar. Click on the calendar title again.

After this you will see a list of years. Select the one you want to install.

After this, you will need to select a month and date on the calendar. All these simple manipulations are enough to change the date in Windows 7. In order to save changes made close all windows by clicking on the “Ok” button.

To make sure that the date has changed, hover over the system clock and look at the message that pops up.

At the top of the pop-up message you will see the date that is set on your computer.

How to change the date in Windows 7 using the command line

To do this, open the Start menu, enter the command “cmd” and click right click mouse using the found program “cmd.exe”. And in the window that opens, select “Run as administrator.”

After this, the command prompt will start with administrator rights, and you can change the date using the “date” command.

Changing the date and time on an Android phone and tablet is a simple operation. But only for those who have mastered the device well and know it like the back of their hand. Did the topic make you smile? Completeness, sir: we were all beginners, and what seems elementary to you once seemed incomprehensible and complex.

This article is for those who are just preparing to become the “Smartphone Guru” and the “God of Android OS”, or rather, for beginners. So, read how to change the date in Android, as well as adjust the time and Timezone.

How to change date and time in Android device

Setting the time and today's date using the system

To change the date and time settings, launch the system settings management tool - the application " Options».

Let's go to the section " date and time" The options that interest us are here. Namely:

Automatic time and date settings.
Automatic time zone setting.
Setting the date manually.
Manual time zone selection.

If you want the phone to install itself current time and number, tap top button shown in the screenshot above. Choose one of two synchronization methods - via network or via GPS.

For the feature to work, the device must periodically connect to the Internet or operator cellular communications. Otherwise, it will have nothing to synchronize with.

If the data is displayed incorrectly, change the time zone in the settings of the same section. Click the button Selecting a time zone» and indicate the region you are currently in.

Or activate " Automatic time zone synchronization over the network", as shown in the screenshot below.

When auto-tuning of the current time and date is enabled, the buttons for manually changing these parameters become inactive. To make them available again, synchronization must be turned off:

After that, go to the section “ Setting the date»:

And mark today's date on your calendar. Or any other. To save, click " Install».

If necessary, do the same operation over time.

What to do if the number is wrong and the system clock is in a hurry or behind

Unnamed devices from the Middle Kingdom often suffer from a similar “disease.” The reason is crooked firmware or low-quality radio elements motherboard. Often nothing can be done about such a defect, since there may not be any other suitable firmware, and repairs will cost more than buying a new device. We have to look for workarounds.

In fact, there is only one way - to install third party application, which will mask the deficiency. My choice fell on ClockSync – free utility, which synchronizes the time and date on the device regardless of system settings.

The only difficulty in using it , it's a necessity to get root rights(a superuser with access to protected system files and functions). Everything else is very simple - just disable synchronization in the device settings (I described how to do this above) and enable it in the utility itself.

For this:

Launch ClockSync and tap the menu button (three dots in the top right corner). Select " Settings».

In the menu section " Automatic synchronization » check « Turn on" Below you can set the synchronization time interval, enable high-precision mode, activate options for saving traffic and battery power, enable auto-tuning of time zones, etc.
If after this the program shows inaccurate time and date, restart the gadget (turn it off and on). That's it.

When using ClockSync, try to turn off your phone or tablet as rarely as possible and connect it to the Internet at least once a day (so as not to miss synchronization cycles). Then the utility’s readings will be as accurate as possible.

Congratulations! You have taken another step towards mastering the functions mobile devices. I hope it wasn't difficult. By the way, I received everything as it is written in the article at the link. Perhaps it will be interesting to you too.

We use time very often in Linux, from the simple task of finding out what time it is, to the more complex task of looking at logs or finding out when this or that event occurred in the system. Everything is tied to time, so it is very important that the clock runs correctly.

Our planet is divided into time zones, this was done with one simple purpose, so that the time anywhere on the planet corresponds to solar time. The time between these zones differs by an hour and there are 24 such zones in total; the time along the zero, Greenwich meridian is taken as the standard.

Therefore, at a certain moment, the time in different parts of the planet will differ by an hour. In this short article we will look at how to change the Linux time zone so that the operating system works correctly with time and can synchronize it correctly over the Internet.

operating room Linux system stores and processes system time in a special Unix format - the number of seconds that have passed since midnight on January 1, 1970. This date is considered the beginning of the Unix era. And it is not your local time that is used, but the time along the Greenwich meridian.

The time zone is used to convert GMT to regional time. This conversion is performed on a per-user basis. This is necessary so that each user can set the correct time for their time zone. This behavior is simply necessary on servers where people from different parts of the world can work on the same machine.

By default, the system may have the wrong time zone set, which will lead to confusion in the event logs and other difficulties. But all this is easy to fix. Next, we'll look at several ways to change the Linux time zone.

Setting the time zone in /etc/localtime

The most popular way to set the time zone for all users and is supported on most distributions is by using a symbolic link /etc/localtime to the desired time zone file. The list of available time zones can be viewed with the command:

ls /usr/share/zoneinfo/

First create backup copy current time zone:

cp /etc/localtime /etc/localtime.bak

ln -sf /usr/share/zoneinfo/Ukraine/Kyiv /etc/locatime

Now you can check the current system time using the date utility:

If you have the rdate utility installed, you can synchronize time with the network:

/usr/bin/rdate -s time-a.nist.gov

All that remains is to synchronize your hardware clock with the new settings; to do this, run the command:

/sbin/hwclock --systohc

If you need to change the time zone only for a specific program or script, just change for it environment variable TZ, for example:

export TZ=Ukraine/Kyiv

This setting is saved only for the current shell session. To change the Linux time zone for a specific user you also need to use environment variable TZ. You just need to add it to the ~/.environment file. This file is read by default when logging in, which means the variable will be available to all programs:

vi ~/.environment

export TZ=Ukraine/Kyiv

Done, now you know how to configure the Linux time zone for a specific user.

Other console utilities

If you do not want to use the method described above, you can use special utilities. It’s just that different distributions use their own utilities. Let's look at options for the most popular distributions.

IN Red Hat Linux:

redhat-config-date

On CentOS and Fedora:

system-config-date

In Slackware or FreeBSD:

dpkg-reconfigure tzdata

In most cases, you will see a dialog box like this:

Here you just need to select the desired time zone and click Enter button. After this, you will need to reboot the system to apply the settings permanently.

Setting the time zone in the GUI

IN Ubuntu distribution and others using Gnome, setting the linux time zone can be done directly in the system settings. To do this, select the item date and time, select your location on the map, or enter a search name in the input field:

In KDE, you can similarly set the time zone in the system settings. Launch the settings utility, open the item Localization, go to section date and time and then open the tab Timezone:

All that remains is to select the time zone in the list and click the Apply button. Here changes should appear instantly.

conclusions

Now you know how to set the time zone in Linux and you can configure not only your home computer but also a server with many users who need a separate time zone for the correct local time. If you have any questions, ask in the comments!

To conclude the video, which explains in detail what time zones are and why they are needed:

What I'm trying to achieve is using int values to change the time and UTC time and get the time from different time zones.

Suggested Int values:

0 = UTC+00:00 1 = UTC+01:00 ...

Logically, it should be something like:

Int timezoneInt = 1; var newDate = DateTime.UtcNow.AddMinutes(timezoneInt*60);

But the problem is that this does not include summer/winter time.

For example:

My location is at UTC+02:00 and the time is 09:20. I need to get UTC+00:00 (which is equal to DateTime.UtcNow and it should be (?) 07:20 AM). Because of daylight saving time, right now.UtcNow is 06:20, so I can't just multiply 60 minutes by the int value, I also need to include the daylight saving time factor somehow.

How did I know to do this, or that I was missing or understood?

EDIT: was marked as a duplicate. Well, I don't see anything that will help change the time using an int value as the timezone.

2 answers

Adjustments for daylight saving time require an extensive time zone database that also records the dates and times that the zone changes to daylight saving time and what the new UTC offset is.

DST databases are not easy to build (or even use in some cases) and need to be manually researched and maintained as they are political rather than technical - countries can change their summer dates as they wish and so the database also needs to record historical dates.

NET Framework has a built-in TimeZoneInfo class (which deprecates the TimeZone class) that uses the time zone database built into Windows, or any other host OS. The Windows time zone database uses full names to identify zones, whereas Linux and tzdb use identifiers such as America/New_York.

Note that in general you should never perform these calculations yourself, as there are always many edges to be aware of. Just use DateTimeOffset .

Additionally, there is no 1:1 mapping between UTC offsets and time zones: different time intervals use the same UTC offset but have different daylight saving time rules (for example, the UK time zone uses UTC+0 as its normal offset UTC, but UTC+1 in summer, but if you see "UTC+1" that could be either a UK zone in summer, or a West African time zone like Algeria, which is UTC+1 but doesn't use daylight saving time at all.

A time zone cannot be represented solely by an offset from UTC. Many time zones have more than one offset due to regulations (aka "daylight saving time"). Offset change dates are also part of the time zone rules, as are any historical offset changes. Many software products,libraries and web services ignore this important detail and,erroneously call the standard or current offset a "zone". This can lead to confusion and misuse data. If possible, use correct terminology.

Bias is simply a number that indicates how far a particular date/time value is or is behind UTC.
- Most offsets are expressed in whole hours.
- But there is a lot that 30 minute offset.
- And there are several that are offset by 45 minutes.
Timezone contains much more:
- A name or identifier that can be used to identify the zone.
- One or more offsets from UTC
- Specific dates and times of zone transition between offsets.
- Sometimes this is a separate display name for a specific language that may be presented to the user.

You can determine the correct offset by taking into account the time zone and date and time. But you can't determine the correct time zone by considering only the offset.

As one of basic parameters time, in addition to the actual time and date, in all computer systems is the concept time zone (Timezone) . To correctly display time in the system, the time zone must be set in accordance with the geographic location of the computer.

In OS Windows family the easiest way is to change the time zone directly from GUI by clicking on the clock icon in the system tray and selecting Changedateandtimesettings(Date and time setting). Next you need to click on the button ChangeTimeZone(Change time zone), select the appropriate one from the list of available time zones and save the changes.

Advice. The time setting window can also be called using the timedate.cpl command.

In Windows 10, the window for changing the time zone setting has been moved to the Settings application (Time and Language -> Date and Time). You can call it by right-clicking on the clock icon and selecting Time and Date Settings from the menu.

In Windows, you can also change the time zone from the command line or the PowerShell console. Specific method depends on the used Windows versions. Let's consider the possible options.

Using these methods, you will have to change the Windows time zone in regions that change to other time zones on October 26, 2014 during.

Right to change time zone

Changing the time zone by default does not require the user to have administrative rights (unlike changing the time/date). You can change this behavior using local security policies ( Local Security Settings - secpol.msc). The setting we are interested in is in the section Security Settings -> Local Policy -> User Rights Assignment(Security Settings -> Local policies-> Assignment of user rights). The policy is called Change the time zone(Change time zone). As you can see, on this moment The system itself, administrators and all ordinary users can change the time zone on the computer. To prohibit ordinary users change the time zone yourself, you need to remove Users from the list of accounts in this policy.

Changing the time zone in Windows 10, 8.1 and 7 – TZUtil utility

To change the time zone in Windows 10 / 8.1 / 7, Windows Server 2016/ 2012 R2/ 2008 R2 uses a special command line utility tzutil. exe (Windows Time Zone Utility) , which first appeared in Windows 7 (on Vista/Server 2008 it is installed as a separate update KB 2556308). Executable file The utilities are stored in the %WINDIR%\System32 directory.

Let's look at the capabilities and features of using the TZUtil utility.

So, run command line(cmd.exe). To find out the current time zone and its identifier (TimeZoneID), run the command:

IN in this example Russian Standard Time is the identifier of the current time zone:

Let's display a list of all time zones with their names and identifiers like this:

Dateline Standard Time
UTC-11
Aleutian Standard Time
Hawaiian Standard Time
Marquesas Standard Time
Alaska Standard Time
UTC-09
UTC-08
Pacific Standard Time (Mexico)
Pacific Standard Time
US Mountain Standard Time
Mountain Standard Time
Mountain Standard Time (Mexico)
Central Standard Time (Mexico)
Canada Central Standard Time
Central America Standard Time
Central Standard Time
Easter Island Standard Time
SA Pacific Standard Time
Eastern Standard Time
Cuba Standard Time
Haiti Standard Time
US Eastern Standard Time
Turks And Caicos Standard Time
Eastern Standard Time (Mexico)
Paraguay Standard Time
Atlantic Standard Time
SA Western Standard Time
Venezuela Standard Time
Central Brazilian Standard Time
Pacific SA Standard Time
Newfoundland Standard Time
Tocantins Standard Time
E. South America Standard Time
Argentina Standard Time
Greenland Standard Time
SA Eastern Standard Time
Montevideo Standard Time
Magallanes Standard Time
Bahia Standard Time
Saint Pierre Standard Time
UTC-02
Mid-Atlantic Standard Time
Azores Standard Time
Cape Verde Standard Time
UTC
GMT Standard Time
Morocco Standard Time
Greenwich Standard Time
W. Europe Standard Time
Central Europe Standard Time
Romance Standard Time
Central European Standard Time
W. Central Africa Standard Time
Sao Tome Standard Time
Jordan Standard Time
GTB Standard Time
Middle East Standard Time
FLE Standard Time
Namibia Standard Time
Syria Standard Time
Israel Standard Time
Egypt Standard Time
Kaliningrad Standard Time
E. Europe Standard Time
West Bank Standard Time
Libya Standard Time
South Africa Standard Time
Sudan Standard Time
Arabic Standard Time
Arab Standard Time
Belarus Standard Time
Russian Standard Time
E.Africa Standard Time
Turkey Standard Time
Iran Standard Time
Arabian Standard Time
Astrakhan Standard Time
Azerbaijan Standard Time
Caucasus Standard Time
Russia Time Zone 3
Mauritius Standard Time
Saratov Standard Time
Georgian Standard Time
Afghanistan Standard Time
West Asia Standard Time
Ekaterinburg Standard Time
Pakistan Standard Time
India Standard Time
Sri Lanka Standard Time
Nepal Standard Time
Central Asia Standard Time
Bangladesh Standard Time
Omsk Standard Time
Myanmar Standard Time
SE Asia Standard Time
Altai Standard Time
North Asia Standard Time
N. Central Asia Standard Time
Tomsk Standard Time
W. Mongolia Standard Time
China Standard Time
North Asia East Standard Time
Singapore Standard Time
W. Australia Standard Time
Taipei Standard Time
Ulaanbaatar Standard Time
North Korea Standard Time
Aus Central W. Standard Time
Tokyo Standard Time
Korea Standard Time
Transbaikal Standard Time
Yakutsk Standard Time
Cen. Australia Standard Time
AUS Central Standard Time
E. Australia Standard Time
Vladivostok Standard Time
West Pacific Standard Time
AUS Eastern Standard Time
Tasmania Standard Time
Lord Howe Standard Time
Magadan Standard Time
Bougainville Standard Time
Norfolk Standard Time
Sakhalin Standard Time
Central Pacific Standard Time
Russia Time Zone 10
Russia Time Zone 11
New Zealand Standard Time
UTC+12
Kamchatka Standard Time
Fiji Standard Time
Chatham Islands Standard Time
UTC+13
Tonga Standard Time
Samoa Standard Time
Line Islands Standard Time

If you want to quickly find and display all available time zones, for example, with UTC offset +2, run the command:

tzutil /l | find /I "utc+02"

Let's change the current time zone (UTC+03:00) Moscow, St. Petersburg, Volgograd - (Russian Standard Time) to (UTC+04:00) Izhevsk, Samara (Russia Time Zone 3). To do this, you need to specify the time zone identifier.

tzutil /s "Russia Time Zone 3"

Let's check that the belt has changed in another way:

To disable daylight saving time for a specific zone, you need to specify the time zone identifier with the suffix _ dstoff, For example

tzutil /s “Pacific Standard Time_dstoff”

After running this command, you will change the computer's time zone and disable the seasonal clock change.

You can also display information about the time zone and seasonal clock settings like this:

Time zone: Current:TIME_ZONE_ID_UNKNOWN Offset: -180min (UTC=LocalTime+Bias)
[Winter time: "RTZ 2 (winter)" Offset: 0min Date: (not specified)]
[Daylight saving time: "RTZ 2 (summer)" Offset: -60min Date: (not specified)]

Managing your time zone from the PowerShell console

You can also get the current time zone settings from the PowerShell console, run the command

::Local

Id: Ekaterinburg Standard Time
DisplayName: (UTC+05:00) Ekaterinburg
StandardName: RTZ 4 (winter)
DaylightName: RTZ 4 (summer)
BaseUtcOffset: 05:00:00
SupportsDaylightSavingTime: True

To see all possible time zones available in Windows, you can use the Powershell command:

::GetSystemTimeZones()
Or

To change the time zone from PowerShell, run the command:

Set-TimeZone -Name "Astrakhan Standard Time"

Automating time zone changes using Powershell

Let's consider a universal Powershell script that allows you to change the time zone on any computer (the script assumes that there are still computers with Windows XP / Windows Server 2003 on your network). This script can be assigned via group policies to all computers in the domain/specific organizational containers (OU). The script determines the OS version and, if it Windows Vista or higher, to change the time zone, use the tzutil.exe command, otherwise, use the option to change the time zone via RunDLL32.exe for Windows XP.

$tmZone = "Russian Standard Time"
$WinOSVerReg = Get-Item "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion"
$WinOSVer = $WinOSVerReg.GetValue("CurrentVersion")
if ($WinOSVer -GE 6)(
tzutil.exe /s $tmZone
) Else (
$param = "/c Start `"Change tmZone`" /MIN %WINDIR%\System32\Control.exe TIMEDATE.CPL,/Z "
$param += $tmZone
$proc = ::Start("CMD.exe", $param)
}

Changing the time zone in Windows XP from the command line

In Windows, information about the value of the current time zone is stored in a registry key

In our case, for example, we can see that the time zone is currently in use - Ekaterinburg Standard Time.

The same information can be obtained with the following request:

reg query HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation

The list of available time zones in Windows XP / Windows Server 2003 is stored in the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones.

To change the current time zone to Moscow (GMT+03:00 -Moscow, St. Petersburg, Volgograd), use the command:

RunDLL32.exe shell32.dll,Control_RunDLL timedate.cpl,/Z Russian Standard Time

Control.exe TIMEDATE.CPL,/Z Russian Standard Time

Let's check that the time zone has changed: