c# - Change default date serialization in WCF

Question

Is there anyway to change the default JSON serialization/deserialization of DateTime in WCF?

Currently, DateTime are serialized into the /Date(1372252162657+0200)/ format, which should've been fine but I'm running into issues when my server is not in UTC (which I can't change).

All date/time data that is being processed by this service is in UTC format. Everything works when the server is in UTC. However, the staging/prod environments are set to GMT+1(Paris) and the serializer is assuming that the dates/times are in GMT+1, completely ignoring the attribute Kind. So as you'd expect calling DateTime.SetKind() and setting it to UTC will not work. In effect, the serialized times are delayed by an hour.

I can either do two-way date conversations (it also makes the same assumption when deserializing so its always GMT+1) conversation of dates: UTC to/from server time, but this is to tedious. So I thought maybe I could just override the default serialization behavior.

Answer 1

Just to expand on tdelepine's code snippet, here the code I've used:

In my WCF JSON Service, I had a (nullable) DateTime value, and wanted my service to return the date in a more readable format, so my iPhone app would be able to interpret it.

Here's what my JSON looked like, after applying a few changes:

Notice the UpdateDateOriginal field, which is the default way that WCF writes DateTimes, and the friendlier UpdateDate field, which I created using the code below.

My original lines looked like this:

[DataMember]
public DateTime? UpdateDateOriginal { get; set; }

... and here are the lines to create the new friendlier UpdateDate JSON value.

[IgnoreDataMember]
public DateTime? UpdateDate { get; set; }

[DataMember(Name = "UpdateDate")]
private string UpdateDateString { get; set; }

[OnSerializing]
void OnSerializing(StreamingContext context)
{
    if (this.UpdateDate == null)
    this.UpdateDateString = "";
    else
    this.UpdateDateString = this.UpdateDate.Value.ToString("MMM/dd/yyyy HH:mm", CultureInfo.InvariantCulture);
}

[OnDeserialized]
void OnDeserializing(StreamingContext context)
{
    if (this.UpdateDateString == null)
    this.UpdateDate = null;
    else
    this.UpdateDate = DateTime.ParseExact(this.UpdateDateString, "MMM/dd/yyyy HH:mm", CultureInfo.InvariantCulture);
}

Actually, you may find it more useful to return DateTime values in ISO8601 format. For example:

UpdateTime: "2014-08-24T13:02:32",

To do this, simply use my code above, but change the string "MMM/dd/yyyy HH:mm" to "s" in both places.

And, if your DateTime values are stored in UTC, but you wanted your WCF services to return the values in the user's local timezone, you can follow my tips here:

Get DateTime in users local timezone

Isn't life easier, with a few simple examples !