In c#, I do this
DateTime.Now.ToString("yyyy-dd-M--HH-mm-ss")
but it gets me the server time. However I also have the offset in this format for example "-04:00". How can I combine the offset to get the local time?
Thanks
If you mean that you want to get the server's system local time including offset, then use the DateTimeOffset.Now property. Then format it as desired.
DateTimeOffset.Now.ToString("yyyy-MM-dd HH:mm:ss zzz")
The zzz specifier produces the offset as a string in the ISO 8601 extended format, that you asked for.
If what you mean is you have a UTC offset from elsewhere and you want to apply it to the current UTC time from the server, then do the following instead:
TimeSpan offset = TimeSpan.Parse("-04:00");
DateTimeOffset now = DateTimeOffset.UtcNow.ToOffset(offset);
string result = now.ToString("yyyy-MM-dd HH:mm:ss zzz");
This takes the current server time, and applies the ToOffset function to adjust to the offset you provided.
Do keep in mind though that an offset is not the same as a time zone. The offset you have might be the one for the current date and time, or it might be for some other date and time in that time zone. For example, US Eastern Time is UTC-4 during daylight saving time, but UTC-5 during standard time. See "Time Zone != Offset" in the timezone tag wiki.
This worked.
DateTime.UtcNow.AddHours(DateTimeOffset.Parse("01/01/0001 00:00:00 -04:00").Offset.TotalHours).ToString("yyyy-dd-M--HH-mm-ss")
This should work
DateTime.UtcNow.AddHours(DateTimeOffset.Parse("01/01/0001 00:00:00 -04:00").Offset.TotalHours).ToString("yyyy-dd-M--HH-mm-ss",CultureInfo. InvariantCulture);
Need to add the directive
using System.Globalization;
Related
I'm converting the UTC time, taken from my local Server time to Central standard time. I have this running on a server in Germany.
Converting the time and date works, but when a library i have converts it to a string it has a wrong Timezone offset.
It comes out as 2019-05-11T14:44:09+02:00
when i need it to be 2019-05-11T14:44:09-06:00
TimeZoneInfo CRtimezone = TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time");
TimeZoneInfo.ConvertTimeFromUtc(DateTime.UtcNow, CRtimezone);
The +02:00 is the UTCoffset for Germany, which i don't want, even the the time and date are correctly in Central Time.
Is there a way to pass or include the offset in the DateTime object?
Is there a way to pass or include the offset in the DateTime object?
No, DateTime structure does not have UTC Offset but DateTimeOffset has. If you really wanna keep your UTC Offset value in your code, I suggest you to work with DateTimeOffset instead of DateTime.
Since it doesn't keep UTC Offset value, when you get it's textual (aka string) representation, you still get the offset value of your server in Germany (includes K, z, zz and zzz specifiers by the way). TimeZoneInfo.ConvertTimeFromUtc method returns a DateTime instance, the offset value you might wanna represent depends on how you want to show it.
One option might be that you might wanna concatenate The Sortable ("s") Format Specifier representation of your DateTime and your TimeZoneInfo.BaseUtcOffset value.
TimeZoneInfo CRtimezone = TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time");
$"{TimeZoneInfo.ConvertTimeFromUtc(DateTime.UtcNow, CRtimezone).ToString("s")}{CRtimezone.BaseUtcOffset}".Dump();
I am trying to figure out the best way of letting the users set the internal DateTime value of the Portable Class Library based on some string parameter they provide. The string parameter has to be a simple format.
So, now I have some considerations.
Is specifying UTC Offset enough for getting the right DateTime
public static DateTime FromUtcOffset(string value)
{
var utcDateTime = DateTime.UtcNow;
var offSet = TimeSpan.Parse(value);
return utcDateTime + offSet;
}
Or is specifying the TimeZone has some advantage over UTC Offset
TimeZoneInfo someTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time");
DateTime convertTimeFromUtc = TimeZoneInfo.ConvertTimeFromUtc(utcDateTime, someTimeZone);
My question is: What would be the right string parameter that can be taken from the user to let him decide what the value of DateTime would be?
Utc Offset
TimeZone
Or any other alternative that's less verbose.
Actually, it depends:
Do you work with network hosts, located in different time zones
Do you store time values for using them in future
Does your library work locally (hence, knows user's timezone)
1+2 basically mean if your time offset might change. If it not (the library is intended for local use only), get local time and don't care about the time offset. However, if the offset might change, usually storing "absolute" time in UTC format should be enough. To do this, you can:
Ask user for UTC time, not their local time
or
Ask for local time + offset (or get the offset from the local time zone, if possible)
Convert it to UTC time and store/process in UTC time
Provide output using local time (using the offset from 1. if it didn't change)
In 1 and 3 you will need a timezone to figure out the time offset. You don't need to know timezone if you already know the offset. Moreover, DateTime itself can store time offset information. It also can tell you if it stores local or UTC time (see DateTime.Kind Property).
How do I convert US-style DateTime such as 5/1/2012 3:38:27 PM returned from the server to user's local time? I am developing for windows phone.
I've tried
DateTime localTime = serverTime.ToLocalTime();
but the result is off a couple of hours. I thought ToLocalTime() will take care of the conversion to any timezone the user are in? Perhaps I need to get the user's timezone info first?
EDIT 1
I think the serverTime is in the PST time zone
EDIT 2
My timezone is GMT +8. I tried the following, but the resulting localTime is 15 hour behind.
TimeZoneInfo localZone = TimeZoneInfo.Local;
DateTime localTime = TimeZoneInfo.ConvertTime(serverTime, localZone);
EDIT 3
This result in 7 hours behind my local time.
TimeZoneInfo localZone = TimeZoneInfo.Local;
DateTime dateTimeKind = DateTime.SpecifyKind(serverTime, DateTimeKind.Utc);
DateTime localTime = TimeZoneInfo.ConvertTime(dateTimeKind, localZone);
EDIT 4
OK I think I am getting there but not sure if this is applicable for all time zones. I think I still have to consider day light saving because the resulting local time is just one hour ahead now.
TimeZoneInfo localZone = TimeZoneInfo.Local;
double offset = localZone.GetUtcOffset(DateTime.Now).TotalHours;
DateTime dateTimeKind = DateTime.SpecifyKind(serverTime, DateTimeKind.Utc);
DateTime localTime = TimeZoneInfo.ConvertTime(dateTimeKind, localZone).AddHours(offset);
But then how do you get DLS is in effect for a particular time zone in Windows Phone? TimeZoneInfo.FindSystemTimeZoneById does not seem to be supported?
For this to work, the DateTime-object serverTime must be of the UTC-form - or at least know what Kindit is. Read all the details around this under the remarks section of this page.
Best of luck!
What does the time represent? If it is a specific moment in time, such as the date and time that something happened, then you should update your server code to return the time in one of the following formats:
// ISO8601 local time with offset.
// get from DateTimeOffset.ToString("o")
2012-05-01T15:38:27-07:00
// ISO8601 UTC time
// get from DateTime.ToString("o") when kind is UTC
2012-05-01T22:38:27Z
It's really important that you do this, because local times can be ambiguous when daylight savings ends. You must either provide the correct offset, (-8 for PST, -7 for PDT), or send as UTC.
There are very few scenarios where sending local time by itself makes sense. If you think you have one, please elaborate about what the time represents.
I am trying to convert a string value to a datetime value but am getting a System.FormatException error. This is because of the timezone info which is part of the date string. Is there any method which will be able to handle this conversion?
string date = "Wed, 04 Jan 2012 20:18:00 EST";
DateTime dt = Convert.ToDateTime(date);
Console.WriteLine(dt.ToString());
I don't believe there's any custom date and time format string which will parse or format a time zone abbreviation. You'll have to strip it out, parse the local part, work out which time zone is meant from the abbreviation (good luck with that - they're ambiguous) and then apply that time zone to the local time to get a UTC value (again, this can be ambiguous).
If you're in control of the format at all, I would try to avoid including time zone information if you can, or include an offset rather than a time zone if that's all that's important (an offset doesn't give the same information of course), or an unambiguous time zone identifier if you really need the time zone. Note that .NET uses the Windows system time zone identifiers; my own Noda Time project uses the more widespread Olson / zoneinfo / tz identifiers, if that's helpful to you.
I get date data from a user. That data is a date (e.g. 4/23/2011) and an hour (0 - 23), representing the time. This date/time that the user selects is a local time.
I need to convert this to a UTC DateTime. I have their GMTOffset for their location. How can I do this?
You should work with the DateTimeOffset structure, specifically, the constructor that takes the DateTime and the TimeSpan that represents the offset.
From there, conversions to/from UTC are a breeze, as the offset is embedded in the structure and not dependent on local system settings.
Note, even though not commonly adhered to, it is recommended to work with DateTimeOffset most of the time, as opposed to DateTime (see the note under the section titled "The DateTimeOffset Structure").
var utcDateTime =
new DateTimeOffset(userDateTime, TimeSpan.FromHours(userUtcOffset)).UtcDateTime;
Of course you can use TimeSpan differently if the GMT offset has minutes / fractions of an hour.
Just use the DateTime.ToUniversalTime in C#, will that do what you want?