Presently .NET API writes dates as composite Ignite objects. Only .NET clients can read such dates: any other client (JDBC, Java, etc) does not understand it without custom deserialization.
It is still possible to configure .NET serialization to write dates as Ignite dates - see DateTime Serialization note. But then Ignite accepts only UTC dates, requiring the application developers to convert local dates to UTC dates and back. This task is not trivial: DateTime.ToUniversalTime uses calendars different from Java (and the .NET calendars are the invalid ones - especially for pre-1990 dates).
The motivation for the current default behavior was probably the desire to keep the Time Zone information: Ignite dates do not store time zones.
In our experience interoperability is more important than storing time zone info.
- Always write .NET dates as portable Ignite dates: get rid of the BinaryReflectiveSerializer.ForceTimestamp flag that currently triggers this behavior.
Keep the ForceTimestamp flag if saving .NET dates as transparent objects seems a useful case.
- Automatically convert Local dates to UTC and back inside Ignite.NET.
Add a BinaryReflectiveSerializer.UtcDate flag to disable this conversion. This prevents loosing the DateTime.Kind property of UTC dates. UtcDate set to true implies the existing behavior: Ignite gets UTC dates and throws a "Date must be in UTC" exception on an attempt to write a Local date. The UtcDate flag is false by default.
- Use NodaTime for UTC<->Local conversions. Noda time uses Java calendars making the conversion truly portable.
- Portable dates is a more frequent use-case than storing time zone info for every date in Ignite. This becomes default behavior and the developers do not need to always explicitly configure it.
- Non-trivial code to make the truly portable UTC<->Local conversion is implemented once inside Ignite instead of having every Ignite.NET application implementing it.
- Dev-List Discussion