Spring-Data-MongoDB: Failed to convert from type after upgrade to 2.0.7 with custom converter

Spring Data MongoDB 2.0.7 considers ZonedDateType as simple type. You need to disambiguate converters into reading and writing converters by adding @ReadingConverter/@WritingConverter.

In your arrangement above, the framework attempts to convert all String values into ZonedDateTime. Instead, you want to represent rather ZonedDateTime objects as String in your MongoDB. So adding @WritingConverter to ZonedDateTimeToStringConverter and @ReadingConverter to the other one fixes your issue.