Guide to DateTime Manipulation (edit)

• Greenwich Mean Time (GMT)
• Coordinated Universal Time (UTC)
• International Organization for Standardization (ISO)

https://www.toptal.com/software/definitive-guide-to-datetime-manipulation

https://www.geeksforgeeks.org/javascript-date-utc-method/

https://css-tricks.com/everything-you-need-to-know-about-date-in-javascript/

How to write the current date time to logging file with the same format?

UTC & ISO in C#

var d1 = DateTime.Now;
var s1 = d1.ToUniversalTime().ToString("yyyy-MM-dd\\THH:mm:ss.fffK"); // Return => 2020-09-01T04:52:11.511Z
Console.WriteLine(s1);

var d2 = DateTime.Now;
var s2 = d2.ToUniversalTime().ToString("ddd, dd MMM yyyy HH:mm:ss 'GMT'"); // Return => Tue, 01 Sep 2020 04:46:11 GMT
Console.WriteLine(s2);

DateTime in C#

using System;
using System.Globalization;

namespace ConsoleApp1
{
 internal class Program
 {
 private const string DateFormatInJavaScript = "yyyy-MM-dd"; //For example: 2019-07-31

 private const string DateTimeString = "yyyy-MM-dd HH:mm:ss"; //For example: 2019-07-31 15:00:23

 private const string DateTimeUTCString = "ddd, dd MMM yyyy HH:mm:ss 'GMT'"; //For example: Tue, 01 Sep 2020 04:46:11 GMT

 private const string DateTimeGMTString = "ddd, dd MMM yyyy HH:mm:ss 'GMT'"; //For example: Tue, 01 Sep 2020 04:46:11 GMT

 private const string DateTimeISOString = "yyyy-MM-dd\\THH:mm:ss.fffK"; //For example: 2020-09-01T04:52:11.511Z

 private const string TimeFormatInJavaScript = "HH:mm"; //For example: 14:31

 private static void Main(string[] args)
 {
 string dateString = "2020-09-01T04:52:11.511Z";

 DateTime dt = DateTime.ParseExact(dateString.Substring(0, 24), DateTimeISOString, CultureInfo.InvariantCulture);

 Console.WriteLine("Before converting:");
 Console.WriteLine(dateString);

 Console.WriteLine("After converting:");
 Console.WriteLine(dt.ToUniversalTime().ToString(DateTimeISOString));
 Console.WriteLine(dt.ToUniversalTime().ToString(DateTimeUTCString));
 Console.WriteLine(dt.ToUniversalTime().ToString(DateTimeGMTString));
 }
 }
}

UTC & ISO in SQL + C#

https://stackoverflow.com/questions/1820915/how-can-i-format-datetime-to-web-utc-format/

https://stackoverflow.com/questions/44788305/c-sharp-convert-datetime-object-to-iso-8601-string

string foo = yourDateTime.ToUniversalTime() .ToString("yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fff'Z'");

UTC & ISO in JavaScript

https://www.w3schools.com/jsref/jsref_obj_date.asp

var d1 = new Date();
var s1 = d1.toISOString();
console.log(s1);
// Return => 2020-09-01T04:34:35.194Z

var d2 = new Date();
var s2 = d2.toUTCString(); // Note: .toUTCString ~ .toGMTString()
console.log(s2);
Tue, 01 Sep 2020 04:34:58 GMT

Web API (C#)

https://stackoverflow.com/questions/31987050/how-to-force-iso-format-yyyy-mm-ddthhmmss-sss-on-the-json-output

public static class WebApiConfig
{
 public static void Register(HttpConfiguration config)
 {
   ...
   config.Formatters
     .JsonFormatter
     .SerializerSettings
     .DateFormatString = "yyyy'-'MM'-'dd'T'HH':'mm':'ss.fffK";
 }
}

Utils (C#)

https://gist.github.com/dmorosinotto/81e8d809a3833b7caf7b3c813703a8e6