Parsing JSON DateTime from Newtonsoft's JSON Serializer

I came up with a different approach which might be useful to some. Basically I create my own CustomDateConverter that I call when I need it. The converter takes 2 parameters, a date format e.g. yyyy-MM-dd HH:mm:ss and a TimeZoneInfo, which allows me to convert the date from UTC to the user's time zone:

public class JSONCustomDateConverter : DateTimeConverterBase
{
    private TimeZoneInfo _timeZoneInfo;
    private string _dateFormat;

    public JSONCustomDateConverter(string dateFormat, TimeZoneInfo timeZoneInfo)
    {
        _dateFormat = dateFormat;
        _timeZoneInfo = timeZoneInfo;
    }
    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(DateTime);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        writer.WriteValue(TimeZoneInfo.ConvertTimeFromUtc(Convert.ToDateTime(value), _timeZoneInfo).ToString(_dateFormat));
        writer.Flush();
    }

You can use it like this:

 var jsonString = JsonConvert.SerializeObject(myObject, Formatting.None, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore, Converters = new List<JsonConverter>() { new JSONCustomDateConverter("yyyy-MM-dd HH:mm:ss", loggedUser.Timezone) } });

Obviously you could remove anything related to time zone if you only want custom date formatting. Let me know it that helped!

As of Newtonsoft Json.Net version 4.5r5 you use the JsonPropertyAttribute Class class and set its ItemConverterType Property property. Usage:

// class to be serialized
public class MyClass
{
    [JsonProperty(ItemConverterType = typeof(JavaScriptDateTimeConverter))]
    public DateTime? DateTime1;
    public DateTime? DateTime2;
}

As I have observed this will set the DateTimeConverter for all properties in this class not just the one before which is declared.

Ran into the same problem, and found a solution based on the link from Adam:

new Date(yourDate.substr(yourDate.indexOf("(") + 1, 13) - 0));

It looks like a Unix timestamp, which javascript is easily able to convert into a date object. The - 0 is simply to make javascript treat the substr output as an integer... I guess you could Number() it as well, if you don't like the looks of - 0

The JSON object contained something like this:

var data = {"CreatedDate":"/Date(1327572000000-1000)/"});

 ///
var oddDateTimeZone = data.CreatedDate;
var utcDateTime = oddDateTimeZone.substr(oddDateTimeZone.indexOf("(")+1, 13);
var utcZone = oddDateTimeZone.substr(oddDateTimeZone.indexOf("-")+1, 4);
var utcDateTimeZone = new Date(Number(utcDateTime)-(Number(utcZone)));

but, still it would be better to fix the JSON object so the date function fired without using something like eval() or window[]. Maybe in jQuery. Not sure.

Don't forget that the offset could be + and not just - for the offset!

Sorry I simplify a bit @James Newton-King

string date = Newtonsoft.Json.JsonConvert.SerializeObject(DateTime.Now);