I need to convert time to "UTC+03:30 Time Zone" in my web application here is UTC date :
DateTime dt = DateTime.UtcNow;
Is there any function to convert UTC to my time zone or not ? I don't want to involve myself writing a new function in my application if there is a function in ASP.NET.
The application might be hosted in different server in the world and that's exactly why I have used UTC date.
I need a function to add 3:30 to the current UTC time.
Are you sure your time zone is really UTC +3:30, all the time, with no daylight savings? If so, you could create a DateTimeOffset with the appropriate offset (3.5 hours). For example:
DateTimeOffset dtOffset = new DateTimeOffset(DateTime.UtcNow,
TimeSpan.FromHours(3.5));
Of course that gives you a DateTimeOffset instead of a DateTime... are you able to use that?
A better solution is to use TimeZoneInfo - for example, you could get the right time zone and call
DateTime local = TimeZoneInfo.ConvertTimeFromUtc(utcDateTime, tzInfo);
... or you could use TimeZoneInfo but still get a DateTimeOffset:
DateTimeOffset dto = TimeZoneInfo.ConvertTime(DateTimeOffset.UtcNow, tzInfo);
Personally I would recommend you use DateTimeOffset if you can, as the meaning of DateTime is somewhat ambiguous and hard to work with correctly.
.NET's date and time handling is a bit of a mess, unfortunately :( I have a project called Noda Time which should improve the state of affairs if we ever complete it, but it's far from production-ready at the moment.
this would let you convert UTC to any timezone
Shared Function FromUTC(ByVal d As Date, ByVal tz As String) As Date
Return (TimeZoneInfo.ConvertTimeBySystemTimeZoneId(d, TimeZoneInfo.Utc.Id, tz))
end function
you're able to get the list of timezones using
For Each timeZone As TimeZoneInfo In tzCollection
Console.WriteLine(" {0}: {1}", timeZone.Id, timeZone.DisplayName)
Next
Related
I have the system date in BST . I want to convert it to UTC. So did the below:
string utcDate= TimeZoneInfo.ConvertTimeToUtc(dt).ToString("dd/MM/yyyy HH:mm:ss");
What I want is to get the zone along with the Date in UTC. Pls consider the daylight savings.
Example: 2019-07-08T23:59:00+01:00.
A few things:
The string format you gave the example of, 2019-07-08T23:59:00+01:00 is part of the ISO 8601 specification. To be precise, it is the "complete date and time of day representation" of the "ISO 8601 Extended Format". It also the format defined by RFC 3339.
In this format, the date and time portion represent the local time, as denoted by the time zone offset portion. In other words, the values are not in UTC, but already adjusted. In your example, 2019-07-08T23:59:00 is the local time and UTC+01:00 is in effect at that time. The corresponding UTC time would thus be an hour earlier, 2019-07-08T22:59:00Z.
You seem to be asking for the date in UTC but with an offset that includes daylight saving time. That is impossible, as UTC does not observe daylight saving time. The offset from UTC is always zero. You can read more about UTC here.
The offset of UTC itself is denoted with Z, but can also be represented with +00:00, which can be thought of as "zero offset from UTC". In other words, if you are referring to UTC time use the Z, and if you are referring to a local time that is aligned to UTC (such as GMT in London in the winter, or Iceland, etc.) use +00:00.
In your question, you say you want the system time in UTC with the offset. I will assume by "system time" you mean the current time of the clock on the system. That is provided by DateTime.UtcNow or DateTimeOffset.UtcNow. These return either a DateTime or DateTimeOffset structure - not a string. Since you wanted a string in a specific format, then you should first ask for the current time, and then format it as a string with ToString:
using System.Globalization;
...
string a = DateTime.UtcNow.ToString("yyyy-MM-dd'T'HH:mm:ssK", CultureInfo.InvariantCulture);
// output example: "2019-07-08T22:59:00Z"
string b = DateTimeOffset.UtcNow.ToString("yyyy-MM-dd'T'HH:mm:sszzz", CultureInfo.InvariantCulture);
// output example: "2019-07-08T22:59:00+00:00"
If what you actually wanted was the local time, such that the offset would be +00:00 in the winter and +01:00 in the summer (in the UK), then use Now instead of UtcNow. This gives the local time in the time zone of the computer where the code is running.
string c = DateTime.Now.ToString("yyyy-MM-dd'T'HH:mm:ssK", CultureInfo.InvariantCulture);
// output example: "2019-07-08T23:59:00+01:00"
string d = DateTimeOffset.Now.ToString("yyyy-MM-dd'T'HH:mm:sszzz", CultureInfo.InvariantCulture);
// output example: "2019-07-08T23:59:00+01:00"
If you actually wanted the time in the UK regardless of what the time zone of the local computer was on, then you'd have to first get the UTC time and then convert it to UK time before creating the string.
TimeZoneInfo tzi = TimeZoneInfo.FindSystemTimeZoneById("GMT Standard Time");
string e = TimeZoneInfo.ConvertTime(DateTime.UtcNow, tzi).ToString("yyyy-MM-dd'T'HH:mm:ssK", CultureInfo.InvariantCulture);
// output example: "2019-07-08T23:59:00"
string f = TimeZoneInfo.ConvertTime(DateTimeOffset.UtcNow, tzi).ToString("yyyy-MM-dd'T'HH:mm:sszzz", CultureInfo.InvariantCulture);
// output example: "2019-07-08T23:59:00+01:00"
In example e, note that a DateTime can't store an arbitrary offset as the result of time zone conversion, and thus you get DateTimeKind.Unspecified assigned to the Kind property, which results in no offset being in the string representation. Thus most of the time you should use a DateTimeOffset (example f) instead.
Also, note the time zone ID of "GMT Standard Time" is the correct ID to use for the UK on Windows platforms. It correctly switches between GMT and BST when appropriate. If you are running .NET Core on non-Windows platforms (Linux, OSX, etc.), then you should use "Europe/London" instead. Or if you are wanting to write code that is platform-neutral then you can use my TimeZoneConverter library, which allows you to provide either form and run on any platform.
In your code example, you didn't call any of the "now" functions, but gave a dt variable. Assuming this is a DateTime, the result of calling TimeZoneInfo.ConvertTimeToUtc will depend on the Kind property of that variable. If it's DateTimeKind.Utc, then no conversion is performed. If it's DateTimeKind.Local or DateTimeKind.Unspecified, then the value is converted from the computer's local time zone to UTC.
Lastly, keep in mind that when talking to an international audience, time zone abbreviations can be ambiguous. I could deduce by "BST" that you meant British Summer Time, but only because you showed a +01:00 offset in your question. "BST" can also stand for "Bangladesh Standard Time" (+06:00), or "Bougainville Standard Time" (+11:00).
I guess you can do something like this:
var dt = DateTime.Now;
string utcDate = dt.ToUniversalTime().ToString("dd/MM/yyyy HH:mm:ss") +
dt.ToString(" zzz");
Output: (I'm in EET)
14/07/2019 20:02:17 +02:00
But be aware that this could be confusing to people. The standard way is that the timezone follows the local date, not the universal date.
I am trying to set a time to EST, and then find what it UCT time is. (We have our reasons).. I have read that "Eastern Standard Time" should take into account the Daylight savings time. But when we check the date, and we know it falls within Daylight Savings time, it still tries to convert for 5 hours instead of 4. Is there any method I am missing? Or do we have to do some manipulation.
DateTimeOffset convertDateTime = new DateTimeOffset(
subbmission.EntryDate,
TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time").BaseUtcOffset);
I added the following bu the boss is not a fan of using this..so any ideas would be greatly appreciated.
if (zone.IsDaylightSavingTime(convertDateTime.DateTime))
{
currentDateTime = convertDateTime.DateTime.AddHours(-1);
}
else
{
currentDateTime = convertDateTime.DateTime;
}
Fundamentally, you're using the wrong approach - if you want to convert to UTC, use TimeZoneInfo.ConvertTimeToUtc(DateTime, TimeZoneInfo). You'll want to be careful around times that are either invalid (because they were skipped) or ambiguous (because the clock went back, and the same local time happened twice).
If you actually want a DateTimeOffset so that you can get both the local and UTC times, you could use call ConvertTimeToUtc then compute the difference between them. It's a shame that TimeZoneInfo doesn't appear to have a "construct a DateTimeOffset based on this DateTime in this time zone" but I can't see it...
As an alternative, you could use my Noda Time project which makes all of this a lot clearer, of course :)
To get the correct offset for a date in the timezone (with or without daylight saing time), i use something like
DateTimeOffset utcOffset = new DateTimeOffset(subbmission.EntryDate.ToUniversalTime(), TimeSpan.Zero);
var zone TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
var correctOffset = zone.GetUtcOffset(utcOffset);
I've been racking my brain all afternoon trying to figure this one out. Essentially, the problem itself seems simple. I'm given a date/time that is representative of a date and time in another time zone (not local). I want to convert this value to a UTC value to store in the database. However, all of the methods I find online seem to point to you either starting with UTC or starting with a local time zone. You can convert TO other time zones from these, but you can't start with anything other than those. As a result, it appears that I'll have to do some kind of convoluted offset math to do what I want. Here is an example of the problem:
var dateString = "8/20/2014 6:00:00 AM";
DateTime date1 = DateTime.Parse(dateString,
System.Globalization.CultureInfo.InvariantCulture);
var currentTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time");
// Now the server is set to Central Standard Time, so any automated offset calculation that it runs will come from that point of view:
var utcDate = date1.ToUniversalTime; // This is wrong
// Similarly, if I try to reverse-calculate it, it doesn't work either
var convertedDate = TimeZoneInfo.ConvertTime(date1, currentTimeZone);
utcDate = convertedDate.ToUniversalTime; // This is also wrong
In essence, I want to somehow tell the system that the datetime object I'm currently working with is from that time zone other than local, so that I know the conversion will be correct. I know that I'll eventually need to figure Daylight Savings Time in there, but that is a problem for another day.
Would this method be of any use to you ?
The TimeZoneInfo.ConvertTime method converts a time from one time zone
to another.
Alternatively, you could use the ConvertTimeToUtc method to simply convert any date (specifying the source time zone) to UTC.
var dateString = "8/20/2014 6:00:00 AM";
DateTime date1 = DateTime.Parse(dateString,
System.Globalization.CultureInfo.InvariantCulture);
var currentTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time");
var utcDate = TimeZoneInfo.ConvertTimeToUtc(date1, currentTimeZone);
The System.DateTime struct only has two bits for storing the "kind" information. That is why you can only have "local" or "universal" or "unknown" (or "magicl local").
Take a look at the System.DateTimeOffset struct. It is like a DateTime, but it also keeps the time zone (offset from (plus or minus) UTC).
I am storing information in a database and setting my POCO's property to DateTime.Now.
When this value is displayed it is appearing as the PST time. I would like it to to display as GMT time.
Do I do something like this to display/store it or is there a better way?
TimeZoneInfo tz = TimeZoneInfo.FindSystemTimeZoneById("GMT");
var GMTTime = TimeZoneInfo.ConvertTimeToUtc(DateTime.Now, tz));
Also it needs to consider Daylight Savings as UK changes its clocks at different times in the year than USA:
UPDATE: I have found that in the TimeZone setting you can pass either GMT Standard Time or Greenwich Mean Time, the first taking into account DST
Store it as UTC. It's designed for universal timezone-independent time.
DateTime currentUtcTime = DateTime.UtcNow;
DateTime localTime = currentUtcTime.ToLocalTime();
DateTime backToUtcAgain = localTime.ToUniversalTime();
Whether a given DateTime is already UTC or local time is determined by DateTime.Kind. You have to keep this in mind when serializing/deserializing DateTime values (e.g from a database) because this information is often not stored and when you get your DateTime back, it will most of the time have the value DateTimeKind.Unspecified, which may cause issues with conversion methods. I just make sure to force DateTimeKind.Utc when I load something in from a persistent data store.
there's DateTime.UtcNow if that meets your needs.
Have a look at DateTimeOffset.
I'd propose to change your DateTime property to this type
MSDN
DateTime vs. DateTimeOffSet
You could add it into an extension method to make it nicer
public static DateTime ConvertToGreenwichMeanTime(this DateTime utcDateTime)
{
return TimeZoneInfo.ConvertTimeFromUtc(utcDateTime, TimeZoneInfo.FindSystemTimeZoneById("GMT Standard Time"));
}
Then just call it
DateTime.UtcNow.ConvertToGreenwichMeanTime();
I am storing all my dates in UTC format in my database. I ask the user for their timezone and I want to use their time zone plus what I am guessing is the server time to figure out the UTC for them.
Once I have that I want to do a search to see what the range is in the database using their newly converted UTC date.
But I always get this exception.
System.ArgumentException was unhandled by user code
Message="The conversion could not be completed because the
supplied DateTime did not have the Kind property set correctly.
For example, when the Kind property is DateTimeKind.Local,
the source time zone must be TimeZoneInfo.Local.
Parameter name: sourceTimeZone"
I don't know why I am getting this.
I tried 2 ways
TimeZoneInfo zone = TimeZoneInfo.FindSystemTimeZoneById(id);
// I also tried DateTime.UtcNow
DateTime now = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Local);
var utc = TimeZoneInfo.ConvertTimeToUtc(now , zone );
This failed so I tried
DateTime now = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Local);
var utc = TimeZoneInfo.ConvertTimeBySystemTimeZoneId(now,
ZoneId, TimeZoneInfo.Utc.Id);
This also failed with the same error. What am I doing wrong?
Edit Would this work?
DateTime localServerTime = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Local);
TimeZoneInfo info = TimeZoneInfo.FindSystemTimeZoneById(id);
var usersTime = TimeZoneInfo.ConvertTime(localServerTime, info);
var utc = TimeZoneInfo.ConvertTimeToUtc(usersTime, userInfo);
Edit 2 # Jon Skeet
Yes, I was just thinking about that I might not even need to do all this. Time stuff confuses me right now so thats why the post may not be as clear as it should be. I never know what the heck DateTime.Now is getting (I tried to change my Timezone to another timezone and it kept getting my local time).
This is what I wanted to achieve: User comes to the site, adds some alert and it gets saved as utc (prior it was DateTime.Now, then someone suggested to store everything UTC).
So before a user would come to my site and depending where my hosting server was it could be like on the next day. So if the alert was said to be shown on August 30th (their time) but with the time difference of the server they could come on August 29th and the alert would be shown.
So I wanted to deal with that. So now I am not sure should I just store their local time then use this offset stuff? Or just store UTC time. With just storing UTC time it still might be wrong since the user still probably would be thinking in local time and I am not sure how UTC really works. It still could end up in a difference of time.
Edit3
var info = TimeZoneInfo.FindSystemTimeZoneById(id)
DateTimeOffset usersTime = TimeZoneInfo.ConvertTime(DataBaseUTCDate,
TimeZoneInfo.Utc, info);
You need to set the Kind to Unspecified, like this:
DateTime now = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Unspecified);
var utc = TimeZoneInfo.ConvertTimeToUtc(now , zone);
DateTimeKind.Local means the in local time zone, and not any other time zone. That's why you were getting the error.
The DateTime structure supports only two timezones:
The local timezone the machine is running in.
and UTC.
Have a look at the DateTimeOffset structure.
var info = TimeZoneInfo.FindSystemTimeZoneById("Tokyo Standard Time");
DateTimeOffset localServerTime = DateTimeOffset.Now;
DateTimeOffset usersTime = TimeZoneInfo.ConvertTime(localServerTime, info);
DateTimeOffset utc = localServerTime.ToUniversalTime();
Console.WriteLine("Local Time: {0}", localServerTime);
Console.WriteLine("User's Time: {0}", usersTime);
Console.WriteLine("UTC: {0}", utc);
Output:
Local Time: 30.08.2009 20:48:17 +02:00
User's Time: 31.08.2009 03:48:17 +09:00
UTC: 30.08.2009 18:48:17 +00:00
Everyone else's answer seems overly complex. I had a specific requirement and this worked fine for me:
void Main()
{
var startDate = DateTime.Today;
var StartDateUtc = TimeZoneInfo.ConvertTimeBySystemTimeZoneId(DateTime.SpecifyKind(startDate.Date, DateTimeKind.Unspecified), "Eastern Standard Time", "UTC");
startDate.Dump();
StartDateUtc.Dump();
}
Which outputs (from linqpad) what I expected:
12/20/2013 12:00:00 AM
12/20/2013 5:00:00 AM
Props to Slaks for the Unspecified kind tip. That's what I was missing. But all the talk about there being only two kinds of dates (local and UTC) just muddled the issue for me.
FYI -- the machine I ran this on was in Central Time Zone and DST was not in effect.
As dtb says, you should use DateTimeOffset if you want to store a date/time with a specific time zone.
However, it's not at all clear from your post that you really need to. You only give examples using DateTime.Now and you say you're guessing that you're using the server time. What time do you actually want? If you just want the current time in UTC, use DateTime.UtcNow or DateTimeOffset.UtcNow. You don't need to know the time zone to know the current UTC time, precisely because it's universal.
If you're getting a date/time from the user in some other way, please give more information - that way we'll be able to work out what you need to do. Otherwise we're just guessing.
UTC is just a time zone that everyone agreed on as the standard time zone. Specifically, it's a time zone that contains London, England. EDIT: Note that it's not the exact same time zone; for example, UTC has no DST. (Thanks, Jon Skeet)
The only special thing about UTC is that it's much easier to use in .Net than any other time zone (DateTime.UtcNow, DateTime.ToUniversalTime, and other members).
Therefore, as others have mentioned, the best thing for you to do is store all dates in UTC within your database, then convert to the user's local time (by writing TimeZoneInfo.ConvertTime(time, usersTimeZone) before displaying.
If you want to be fancier, you can geolocate your users' IP addresses to automatically guess their time zones.