Why can DateTime.MinValue not be serialized in timezones ahead of UTC?

Solution 1:

The main problem is DateTime.MinValue has DateTimeKind.Unspecified kind. It is defined as:

MinValue = new DateTime(0L, DateTimeKind.Unspecified);

But this is not a real problem, this definition leads to problem during serialization. JSON DateTime serialization done through:

System.Runtime.Serialization.Json.JsonWriterDelegator.WriteDateTime(DateTime value)

Unfortunately it is defined as:

...

if (value.Kind != DateTimeKind.Utc)
{
    long num = value.Ticks - TimeZone.CurrentTimeZone.GetUtcOffset(value).Ticks;
    if ((num > DateTime.MaxValue.Ticks) || (num < DateTime.MinValue.Ticks))
    {
        throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(XmlObjectSerializer.CreateSerializationException(SR.GetString("JsonDateTimeOutOfRange"), new ArgumentOutOfRangeException("value")));
    }
}

...

So it doesn't take into account Unspecified and treats it as Local. To avoid this situation you can define your own constant:

MinValueUtc = new DateTime(0L, DateTimeKind.Utc);

or

MinValueUtc = DateTime.MinValue.ToUniversalTime();

It looks weird of course, but it helps.

Solution 2:

Try to add this on any DateTime Member

[DataMember(IsRequired = false, EmitDefaultValue = false)]

Most of these erros happens because the default value of the datetime is DateTime.MinValue which is from year of 1 and the JSON serialization is from year 1970.