How Do I Convert IANA zone + datetime to UTC + Offset using NodaTime - c#

I have local time in string format: "yyyy-MM-dd HH:mm:ss" and an IANA Time Zone for that time (e.g. "Europe/London").
How do I convert that in C#, maybe using NodaTime, to a UTC+TimeZone Offset string
e.g. "yyyy-MM-dd HH:mm:ss+01:00" ?
I don't even know where to start!
This is as far as I get (I am afraid I'm new to C sharp):
I understand I need to convert it to an instant, but just can't get to grips with the library.
string dateTime = "2014-12-31 12:30:00";
string IANA = "Europe/London";
Instant instDateTime = NodaTime.Instant.FromDateTimeUtc(Convert.ToDateTime(dateTime));
string outputUTC = string.Format("yyyy-MM-dd HH:mm:ssZ", instDateTime);
Thanks to Matt (see answer below), I now have the functions I needed (Note that in the end what I needed was UTC and not date time + offset):
What is a little worrying is that is says that Europe/Moscow is UTC+04:00, whereas it is actually UTC+03:00 since 26 October 2014.
static void Main(string[] args)
{
string dateTime = "2014-12-31T12:30:00";
string timeZone = "Europe/Moscow";
Console.WriteLine(timeZone + " Local time '" + dateTime + "' to Zulu time");
Console.WriteLine(ConvertIANALocalTimeToZulu(timeZone, dateTime));
Console.WriteLine();
Console.WriteLine("Zulu time '" + dateTime + "' to " + timeZone + " local time");
Console.WriteLine(ConvertZuluTimeToIANALocalTime(timeZone, dateTime));
Console.ReadLine();
}
static string ConvertIANALocalTimeToZulu(string timeZoneIANA, string localDateTime)
{
var pattern = LocalDateTimePattern.CreateWithInvariantCulture("yyyy-MM-ddTHH:mm:ss");
LocalDateTime ldt = pattern.Parse(localDateTime).Value;
ZonedDateTime zdt = ldt.InZoneLeniently(DateTimeZoneProviders.Tzdb[timeZoneIANA]);
Instant instant = zdt.ToInstant();
ZonedDateTime zulu = instant.InUtc();
////string output = zulu.ToString("yyyy-MM-dd HH:mm:sso<m>", CultureInfo.InvariantCulture);
string output = zulu.ToString("yyyy-MM-ddTHH:mm:ss", CultureInfo.InvariantCulture);
return output;
}
static string ConvertZuluTimeToIANALocalTime(string timeZoneIANA, string zuluDateTime)
{
var pattern = InstantPattern.CreateWithInvariantCulture("yyyy-MM-ddTHH:mm:ss");
Instant instant = pattern.Parse(zuluDateTime).Value;
ZonedDateTime zdt = instant.InZone(DateTimeZoneProviders.Tzdb[timeZoneIANA]);
////string output = zdt.ToString("yyyy-MM-dd HH:mm:sso<m>", CultureInfo.InvariantCulture);
string output = zdt.ToString("yyyy-MM-ddTHH:mm:ss", CultureInfo.InvariantCulture);
return output;
}

It's unclear from your question if you meant that the original value was in UTC or in local time.
If it's in UTC, then do the following:
string dateTime = "2014-12-31 12:30:00";
string timeZone = "Europe/London";
var pattern = InstantPattern.CreateWithInvariantCulture("yyyy-MM-dd HH:mm:ss");
Instant instant = pattern.Parse(dateTime).Value;
ZonedDateTime zdt = instant.InZone(DateTimeZoneProviders.Tzdb[timeZone]);
string output = zdt.ToString("yyyy-MM-dd HH:mm:sso<m>", CultureInfo.InvariantCulture);
If it's in local time, then do this instead:
string dateTime = "2014-12-31 12:30:00";
string timeZone = "Europe/London";
var pattern = LocalDateTimePattern.CreateWithInvariantCulture("yyyy-MM-dd HH:mm:ss");
LocalDateTime ldt = pattern.Parse(dateTime).Value;
ZonedDateTime zdt = ldt.InZoneLeniently(DateTimeZoneProviders.Tzdb[timeZone]);
string output = zdt.ToString("yyyy-MM-dd HH:mm:sso<m>", CultureInfo.InvariantCulture);
Also - you should note that in December, London is on GMT (UTC+00:00) - so the output of either function will be "2014-12-31 12:30:00+00:00" for the values you provided.

Related

System.FormatException: String was not recognized as a valid DateTime (DateTime Format yyyyMMdd:HHmmss)

I have a date time format of yyyyMMdd:HHmmss. I receive the datetime from a device and I can confirm that the format is yyyyMMdd:HHmmss.
For example I get datetime as 20180331:162308. I tried to convert to 03/31/2018 04:23 PM format by using below code:
string localDateTime =
Convert.ToString(protocol.GetParameter(Parameter.localmdmdatetimestr_3043));
string formatString = "yyyyMMdd:HHmmss";
protocol.Log(
"QA" + protocol.QActionID + "|DateTime|localDateTime" + localDateTime,
LogType.Error,
LogLevel.NoLogging);
DateTime LocalDt = DateTime.ParseExact(
localDateTime,
formatString,
CultureInfo.InvariantCulture);
But instead get
System.FormatException: String was not recognized as a valid DateTime
error.
As per your requirement
string localDateTime = Convert.ToString("20180331:162308");
string formatString = "yyyyMMdd:HHmmss";
DateTime LocalDt = DateTime.ParseExact(
localDateTime,
formatString, CultureInfo.InvariantCulture);
Console.WriteLine(LocalDt);
var test = LocalDt.ToString("yyyy/MM/dd HH:mm tt", CultureInfo.InvariantCulture);
Console.WriteLine(test);
Console.ReadLine();

Issue in Converting String to DateTime Format

I am unable to convert the string values that has been extracted from the ddl to a DateTime datatype.
The Error Message
An exception of type 'System.FormatException' occurred in mscorlib.dll
but was not handled in user code. Additional information: String was
not recognized as a valid DateTime.
I only require the date to be updated in the SQL database.
This is the an image of the DataDictionary and the Attribute I require would be the birthdate
These are my current codes that get and convert the date time.
string birth = ddlDay.SelectedItem.Value + "-" + ddlMonth.SelectedItem.Value + "-" + ddlYear.SelectedItem.Value;
DateTime birthDate = DateTime.ParseExact(birth, "dd-MMMM-yyyy", System.Globalization.CultureInfo.InvariantCulture);
objCustomer.birthDate = birthDate;
string date = "01/08/2008";
DateTime dt = Convert.ToDateTime(date);
Console.WriteLine("Year: {0}, Month: {1}, Day: {2}", dt.Year, dt.Month, dt.Day);
Instead of ParseExact you could use TryParse to be safe. ie:
var ddlDaySelectedItemValue = "29";
var ddlMonthSelectedItemValue = "Feb"; // February, 2, 02
var ddlYearSelectedItemValue = "2016";
DateTime birthDate;
string birth = ddlYearSelectedItemValue + " " + ddlMonthSelectedItemValue + " " + ddlDaySelectedItemValue;
if (DateTime.TryParse(birth, System.Globalization.CultureInfo.InvariantCulture, DateTimeStyles.None, out birthDate))
{
objCustomer.birthDate = birthDate;
}
Change your code to:
DateTime.ParseExact(birth, "dd-MM-yyyy", System.Globalization.CultureInfo.InvariantCulture);

String which is not in datetime format to DateTime

I have a string which is not in a datetime format eg:20160503. How can i change it to Datetime. I tried using Substring. It is working.Is there any more efficient way? Below is what I have right now.
string a = "20160503";
int b = Convert.ToInt32(a.Substring(0, 4));
int c = Convert.ToInt32(a.Substring(4, 2));
int d = Convert.ToInt32(a.Substring(6, 2));
string date = b + "/" + c + "/" + d;
DateTime result = new DateTime();
DateTime.TryParse(date, out result);
Since you know the exact format of your datetime, you could try to use the ParseExact DateTime's method.
var dt = DateTime.ParseExact(a,"yyyyMMdd",CultureInfo.InvariantCulture);
For further info, please have a look here.
Try somthing like this:
Define your own parse format string to use.
string formatString = "yyyyMMdd";
string sample = "20160503";
DateTime dt = DateTime.ParseExact(sample,formatString,null);
Thanks for your replies. Finaly I ended up using DateTime.TryParseExact
string dateString = "20150503";
DateTime dateValue = new DateTime();
DateTime.TryParseExact(dateString, "yyyyMMdd", new CultureInfo("en-US"), DateTimeStyles.None, out dateValue);

convert C# date time to string and back

I'm converting C# date time to string. Later when I convert it back to DateTime object it appears that they are not equal.
const string FMT = "yyyy-MM-dd HH:mm:ss.fff";
DateTime now1 = DateTime.Now;
string strDate = now1.ToString(FMT);
DateTime now2 = DateTime.ParseExact(strDate, FMT, CultureInfo.InvariantCulture);
Console.WriteLine(now1.ToBinary());
Console.WriteLine(now2.ToBinary());
Here is the example. Looks like everything is included in string format, when I print date both displays the same, but when I compare objects or print date in binary format I see the difference. It looks strange to me, could you please explain what is going on here?
Here is the output for the code above.
-8588633131198276118
634739049656490000
You should use the roundtrip format specifier "O" or "o" if you want to preserve the value of the DateTime.
The "O" or "o" standard format specifier represents a custom date and time format string using a pattern that preserves time zone information. For DateTime values, this format specifier is designed to preserve date and time values along with the DateTime.Kind property in text. The formatted string can be parsed back by using the DateTime.Parse(String, IFormatProvider, DateTimeStyles) or DateTime.ParseExact method if the styles parameter is set to DateTimeStyles.RoundtripKind.
Using your code (apart from changing the format string):
const string FMT = "O";
DateTime now1 = DateTime.Now;
string strDate = now1.ToString(FMT);
DateTime now2 = DateTime.ParseExact(strDate, FMT, CultureInfo.InvariantCulture);
Console.WriteLine(now1.ToBinary());
Console.WriteLine(now2.ToBinary());
I get:
-8588633127598789320
-8588633127598789320
Oded's answer is good but it didn't work for me for UTC dates. In order to get it to work for UTC dates, I needed to specify a DateTimeStyles value of "RoundtripKind" so that it didn't try to assume it was a local time. Here is the updated code from above:
const string FMT = "O";
DateTime now1 = DateTime.Now;
string strDate = now1.ToString(FMT);
DateTime now2 = DateTime.ParseExact(strDate, FMT, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind);
Console.WriteLine(now1.ToBinary());
Console.WriteLine(now2.ToBinary());
Note, this works for both UTC and local dates.
2 things:
You can use the ParseExact overload that takes a DateTimeStyle parameter in order to specify AssumeLocal.
There will still be a small difference between now1 and now2 unless you increase the precision to 7 digits instead of 3: "yyyy-MM-dd HH:mm:ss.fffffff"
const string FMT = "yyyy-MM-dd HH:mm:ss.fffffff";
DateTime now1 = DateTime.Now;
string strDate = now1.ToString(FMT);
DateTime now2 = DateTime.ParseExact(strDate, FMT, CultureInfo.InvariantCulture, DateTimeStyles.AssumeLocal);
Console.WriteLine(now1.ToBinary());
Console.WriteLine(now2.ToBinary());
Even without the above changes, the calculated difference between now1 and now2 appears small, even though the binary values do not appear similar.
TimeSpan difference = now2.Subtract(now1);
Console.WriteLine(difference.ToString());
If you dont need the string to be human-readable (like, you want to cipher it before storage), you can just call string str = dt1.ToBinary().ToString(); and DateTime dt2 = DateTime.FromBinary(long.Parse(str));
DateTime now1 = DateTime.Now;
string strDate = now1.ToBinary().ToString();
DateTime now2 = DateTime.FromBinary(long.Parse(strDate));
Console.WriteLine(now1.ToBinary());
Console.WriteLine(now2.ToBinary());
Just use this code it convert date time to string and string to date time
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace DateTimeConvert
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
label1.Text = ConvDate_as_str(textBox1.Text);
}
public string ConvDate_as_str(string dateFormat)
{
try
{
char[] ch = dateFormat.ToCharArray();
string[] sps = dateFormat.Split(' ');
string[] spd = sps[0].Split('.');
dateFormat = spd[0] + ":" + spd[1] + " " + sps[1];
DateTime dt = new DateTime();
dt = Convert.ToDateTime(dateFormat);
return dt.Hour.ToString("00") + dt.Minute.ToString("00");
}
catch (Exception ex)
{
return "Enter Correct Format like <5.12 pm>";
}
}
private void button2_Click(object sender, EventArgs e)
{
label2.Text = ConvDate_as_date(textBox2.Text);
}
public string ConvDate_as_date(string stringFormat)
{
try
{
string hour = stringFormat.Substring(0, 2);
string min = stringFormat.Substring(2, 2);
DateTime dt = new DateTime();
dt = Convert.ToDateTime(hour+":"+min);
return String.Format("{0:t}", dt); ;
}
catch (Exception ex)
{
return "Please Enter Correct format like <0559>";
}
}
}
}

take time and append to date to make datetime?

Say I have the following:
string fromTime = "8:00am";
string someDate = "06/01/2012";
I want to end up doing this:
DateTime dt = Convert.ToDateTime(someDate + someTime);
Basically I want to take a date and add the time to it with the result for the above to be
06/01/2012 8:00am
But have it stored in a datetime variable. Is this possible?
You could use the DateTime.TryParseExact method which allows you to specify a format when parsing:
class Program
{
static void Main()
{
string s = "06/01/2012 8:00am";
string format = "dd/MM/yyyy h:mmtt";
DateTime date;
if (DateTime.TryParseExact(s, format, CultureInfo.InvariantCulture, DateTimeStyles.None, out date))
{
Console.WriteLine(date);
}
}
}
Try this:
DateTime dt = DateTime.ParseExact(someDate + " " + someTime, "MM/dd/yyyy h:mmtt", CultureInfo.InvariantCulture);

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