How to set time zone automatically using current location in C# - c#

I need to set my system's time zone automatically using location. when I travel to some other places my system time zone will remains same.When I open my WPF Application and if the internet is connected, is it possible to automatically set the time zone of my system by getting the current time zone by location?

You would need to
Have a reliable source of location information.
Pass the coordinates determined in step 1 to one of these techniques to get an IANA time zone.
Translate the IANA time zone to a Windows time zone using CLDR mappings, as described here.
Set the Windows time zone using one of the approaches from this answer.
Explain to your users why your application is doing something that is really their own responsibility (or the operating system's responsibility). In other words, don't be sneaky about this. If you're going to do it, it should be a prominent feature of your application, and you should have the user's confirmation before changing anything. Remember, the time zone setting is global for the machine, not just for your application.
IMHO, if this isn't a system utility you're writing, then you should just use the determined time zone instead of trying to set the system to it.

Step one: you need to get the users location I suggest HostIP
Step two: get the time zone of that location Google maps time zone API
then you have to stitch those together.

Related

I have TimeZoneId in Russian. How to get equivalent in English?

My app works with a public calendar via CalDAV protocol (let's call it CalDAV calendar) which returns events in iCalendar format. One user started to create events in that calendar using Outlook localized to Russian language. It happened that Outlook put TZID field in the CalDAV calendar event in Russian language, as follows:
BEGIN:VCALENDAR
PRODID: some prod id
VERSION:2.0
BEGIN:VTIMEZONE
TZID:(UTC+03:00) Москва\, Санкт-Петербург
BEGIN:STANDARD
DTSTART:19710101T000000
TZOFFSETFROM:+0300
TZOFFSETTO:+0300
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
ORGANIZER;CN=UserName:MAILTO:username#mail.com
RRULE:FREQ=DAILY;UNTIL=20230108T100000Z
DTSTAMP:20230109T101100Z
UID:russiantz001
SEQUENCE:0
SUMMARY:Тест с 6 по 8 в 13 00 - 13 30
DTSTART;TZID="(UTC+03:00) Москва, Санкт-Петербург":20230106T130000
DTEND;TZID="(UTC+03:00) Москва, Санкт-Петербург":20230106T133000
DESCRIPTION:Russian TZ
CalDAV calendar treats events correctly. To deserialize iCalendar event I am using iCal.NET library which in turn uses NodaTime method DateTimeZoneProviders.Tzdb.GetZoneOrNull(TimeZoneId) to convert time from a time zone to UTC. It searches all time zone providers (IANA, BCL, serialization, etc) to see if TimeZoneId matches. Unfortunately, NodaTime does not understand TimeZoneId in Russian.
My question: how to get a correct English equivalent of the TimeZoneId in Russian generated by the localized Outlook?
.NET method FindSystemTimeZoneById throws exception that TimeZoneId is not found.
My app works in Linux environment. Therefore I cannot use Windows registry HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Time Zones records. Moreover, to use registry records Windows should have been localized to the Russian language which would not happen for sure.
For now I am thinking just to use (UTC+03:00) prefix of the time zone Id in Russian, but I am not sure if this is right decision. For example, will time zone offset be correct during daylight saving period?
I would greatly appreciate any link or hint how to solve this conversion issue.
Time zone IDs should never be localized. What you have in the TZID field appears to be a time zone display name, not an ID. The application that created that file is incorrectly using the DisplayName property of the TimeZoneInfo object where it should be using Id property instead.
The correct Windows ID that should be showing in the file is "Russian Standard Time". Or it could (preferably) show the equivalent IANA time zone ID, which is "Europe/Moscow". They should be those exact strings and not translated to Russian.
The iCal format itself (and anything consuming it) doesn't care about this because it is strictly looking at the TZID field as it exists within the file. But anything else you use it for absolutely will.
The original application needs to be updated to return a time zone identifier instead of a display name in the TZID field.
Just using the time zone offset might be sufficient - but it may not always be. For example, if the time zone is one that changes offsets due to daylight saving time, the offset in the display name won't necessarily be the correct offset in effect for the event in the calendar.
The offset might also be different on the start time than on the end time, if the event crosses a DST transition. Moreover, if the event is recurring, the offset can be different between occurrences of events.
Then again, that particular time zone doesn't use DST (at least it doesn't presently), so you may never encounter such cases.

changing the system time format on windows 7

Well I am looking for a method to change the default windows 7 time format for a system.
So if a system uses like 10PM or 10 AM as default time notation, then i like to change that system to 10:00 or 22:00.
I know how to do it through the GUI, but in my case our software (C#) has to check if time notation is OK and if it is not change it by usage of
C#, registry editing, vbscript, commanline or Powershell, or some specific .exe file
The software we wrote allready makes usage of external progs / languages (vbscript/powershell).
But the problem is so far i have not found a method to do this other then taking over a remote screen.
Perhaps someone knows how to do this ?
The same counts for time zone, and date notation.
You may change the system time format using following code:
RegistryKey rk = Registry.CurrentUser.OpenSubKey(#"Control Panel\International", true);
rk.SetValue("sTimeFormat", "hh:mm:ss"); // HH for 24hrs, hh for 12 hrs
But IMO, this would not be a good practice for an application to change the system user's settings without the consent of the user.
I found this link that shows it being done via vb.net but you would have to translate it. or you could compile this to an exe and run it from a shell. http://www.access-programmers.co.uk/forums/showthread.php?t=152624
The property way to do this in .NET is with code such as the following:
CultureInfo newCultureInfo = (CultureInfo)System.Threading.Thread.CurrentThread.CurrentCulture.Clone();
newCultureInfo.DateTimeFormat.ShortDatePattern = shortDateFormat;
newCultureInfo.DateTimeFormat.LongTimePattern = longTimeFormat;
Thread.CurrentThread.CurrentCulture = newCultureInfo;
Regarding the solution using the "Control Panel\International" registry key (sorry, can't comment due to not have a 50 reputation):
This doesn't appear to affect the existing process, only new processes created after changing the registry. And obviously code assuming registry values (i.e. implementation details) could break in a future version of windows.
Also the code should Dispose the RegistryKey object. It would be better written with a using block.
Regarding if you should do this, while it would be unlikely an app would want to change the time date format (maybe an app that's an improved way of setting system info), it would be very reasonable to need to do this in an automated test. It's a common bug for code to depend on the default time/date format, so setting them to non-default values, or testing code with various time/date formats could be a good idea.

How do I get the correct modified datetime of a FAT32 file, regardless of timezone in .NET?

Please read this question fully and carefully before answering. The answer is not as simple as it might appear.
I am writing a program that needs to keep track of the modified datetime of files, some of which are stored on an external FAT32 drive. The program is being run on various Windows 7 machines.
The problem is the UTC modified datetime changes when the current UTC offset changes. Specifically, when we go from New Zealand Standard Time (UTC+12) to New Zealand Daylight Time (UTC+13) and back again. That is not a typo - the UTC modified datetime changes. It shouldn't, that is kind of the point of UTC, but it does. This appears to be a limitation of the FAT32 file system - files on NTFS work fine.
Console.WriteLine(DateTime.Now.ToString() + (DateTime.Now.IsDaylightSavingTime() ? " Daylight" : " Standard"));
Console.WriteLine(new FileInfo(args[0]).LastWriteTimeUtc.ToString("yyyyMMdd HH mmss"));
System timezone is New Zealand and the system date is 9 April 2012 which is New Zealand Standard Time.
C:\Dev\UtcModifiedDatetime\bin\Debug>UtcModifiedDatetime.exe M:\Test1\Test.txt
2012-04-09 3:53:46 pm Standard
20120409 03 5316
Now set the system date to 1 March 2012 which is New Zealand Daylight Time. Note that I have renamed the directory that contains the test file. This is important because otherwise Windows will cache the modified datetime of the file. I wasted a lot of time before I figured that out.
C:\Dev\UtcModifiedDatetime\bin\Debug>UtcModifiedDatetime.exe M:\Test2\Test.txt
2012-03-01 3:54:13 pm Daylight
20120409 02 5316
Now set the system date back to 9 April 2012 and change the timezone to Adelaide (UTC+09:30).
C:\Dev\UtcModifiedDatetime\bin\Debug>UtcModifiedDatetime.exe M:\Test3\Test.txt
2012-04-09 1:27:21 pm Standard
20120409 06 2316
So how can I get the correct modified datetime? I could try and figure out if the file is on a FAT32 file system and if it is daylight saving time make a one hour adjustment, but even if I could get that to work it would be a horrible ugly hack. Will using a low level system call work (I suspect not because the problem seems to be at the OS level)? Can I change the timezone of the process, without changing it on the whole machine? Is there any other way?
The problem is, FAT32 filesystem stores file time as a local time. Thus UTC time is a calculated time which takes DST into account, which results in a different UTC time. In general this problem is so complex, it's unsolvable.
For example you will need to store real UTC file modification time in a separate file, which must be synchronized on each machine before external drive is removed. If sync will not be preformed at least once, then it can't be considered correct. And there is no simple way to enforce that to users.

Confirming system time

I'm trying to make a system that basically allows me to shove a DLL in an installation and some code in an exe that allows me to release all of my future programs as beta releases for a while.
Now the problem is of course if I'd want to do that, i'd need to choose until when the program is valid. Which is fine, except that by changing your system clock, you can easily bypass the system.
Now, I'd like to hear what people generally do for something like this.
I've been trying a few approaches such as contacting a site to give the timestamp and compare that, which would be fine if it didn't always increase the program start time by over 9000
and and the fact that people would then not be able to use it if they're not connected to the internet.
Any suggestions are much appreciated.
This is not 100% guaranteed solution but it will take you there
You will need to implement these things in the config file (Why Config file, because if user deletes it your app won't run). Also encrypt all the following data.
Store the Date and Time on which application ran.
Store the exact amount of time for which application ran.
By doing so you can avoid:
If user change the computer time, you will come to know that, as your app is logging Date and Time, it might overlap the earlier time, say user ran app on 6th and 10th of month, and then he reverts date to 7th, you will come to know about it.
Secondly user can change the date on every run to single date, in that case the total duration used will help you. Say user set date to 1st of month every time he runs it, in that case, he can use app for 24 Hrs only not more than that.
Other options like
Checking time from External Server (Flaw: Requires internet access)
Storing Time in Registry (Flaw: User can easily manipulate registry)
Hope this helps you.
If your software can access some network share on some local server/nas, you can create a new file on this network share, and this file will have a creation time set using the clock of the server/nas, so you can compare the time set on the server/nas to the time of the local computer.
Or you can also save somewhere (a file, in the registry, in a DB) the last time of the last execution, and if the clock go back in time, then you can lock the application and require further assistance :-)

How can I change a Windows user's regional settings/date format?

I use a VB6/COM+ application which outputs date/time values based on the short date settings in the Control Panel, Regional Settings, for the user that runs it. The program that then parses that output has a configurable setting for the date format it expects, and presents in the UI.
e.g. If the regional setting for the user is set to mm/dd/yyyy, and it outputs 06/18/2009, the application expecting "18/06/2009" fails with "String was not recognized as a valid DateTime".
As we usually run this application as a service account, which we have not logged in as interactively to create a profile, we generally set the correct date format and then tick the "Apply all settings to the current user account and the default user profile" option.
I would like to be make the C# configuration utility I have written for this mess to be able to set the date format programmatically for a given user.
Edit
I would like nothing more than to change the code, but do not have the ability to do so at this time.
I also know that what I am asking is a bad thing to do. With regards to "it should be the user's choice" - I am that user, as I create it explicitly for the task; I just want to set the date format by a scripted method, rather than having to do the clicking myself.
This is specifically discouraged by Microsoft. Any solution you may come up with will be a filthy hack that will probably stop working soon.
Think of it this way: who are you to decide those settings? Don't you think that's the user's decision?
Back on topic: find an unambiguous format for the applications to communicate in, such as YYYYMMDD. The application that displays can then simply respect the actual user settings, as it should.
But, since you can't change it, just poke into the registry:
Current user:
HKEY_CURRENT_USER\Control Panel\International
Specific user:
HKEY_USERS\(user SID)\Control Panel\International
Default user:
HKEY_USERS\.DEFAULT\Control Panel\International
sShortDate is probably the value you want to change.
If you are going to modify the profile to suit your needs, why not just ignore the profile settings and hardcode the format you want in your app?
code:
Imports System.Threading
Thread.CurrentThread.CurrentCulture = New CultureInfo("en-US", False)
Microsoft.Win32.Registry.SetValue("HKEY_CURRENT_USER\Control Panel\International", "sShortDate", "M/d/yyyy")
While persistently changing a user's culture (regional settings) is to be done cautiously, there are legitimate use cases.
On Windows 8 and Windows Server 2012 and above, Windows PowerShell comes with the
Set-Culture cmdlet, which is the programmatic equivalent of choosing a different region via Control Panel (intl.cpl).
For instance, Set-Culture fr-CA is the equivalent of interactively choosing region French (Canada) for the current user.
Caveat: Mixed cultures such as en-DE (sic) appear not to work as of Windows PowerShell v5.1 - see this answer of mine.
While it won't be fast, it is possible to call PowerShell commands from C#.

Categories

Resources