Formatting DateTime in ASP.NET Core 3.0 using System.Text.Json

Question

I am migrating a web API from .NET Core 2.2 to 3.0 and want to use the new System.Text.Json. When using Newtonsoft I was able to format DateTime using the code below. How can I accomplish the same?

.AddJsonOptions(options =>     {         options.SerializerSettings.DateTimeZoneHandling = Newtonsoft.Json.DateTimeZoneHandling.Utc;         options.SerializerSettings.DateFormatString = "yyyy'-'MM'-'dd'T'HH':'mm':'ssZ";     }); 

Answer 1

Solved with a custom formatter. Thank you Panagiotis for the suggestion.

public class DateTimeConverter : JsonConverter<DateTime> {     public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)     {         Debug.Assert(typeToConvert == typeof(DateTime));         return DateTime.Parse(reader.GetString());     }      public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)     {         writer.WriteStringValue(value.ToUniversalTime().ToString("yyyy'-'MM'-'dd'T'HH':'mm':'ssZ"));     } }   // in the ConfigureServices() services.AddControllers()     .AddJsonOptions(options =>      {          options.JsonSerializerOptions.Converters.Add(new DateTimeConverter());      }); 

Answer 2

Migrating to Core 3 I had to replace System.Text.Json to use Newtonsoft again by :

services.AddControllers().AddNewtonsoftJson(); 

But I was having same issue with UTC dates in an Angular app and I had to add this to get dates in UTC:

services.AddControllers().AddNewtonsoftJson(        options => options.SerializerSettings.DateTimeZoneHandling = DateTimeZoneHandling.Utc); 

In your case you should be able to do this:

services.AddControllers().AddNewtonsoftJson(options =>     {         options.SerializerSettings.DateTimeZoneHandling = Newtonsoft.Json.DateTimeZoneHandling.Utc;         options.SerializerSettings.DateFormatString = "yyyy'-'MM'-'dd'T'HH':'mm':'ssZ";     }); 

It works and I hope it helps...