If you have a field type of Date, when you insert a new date the database stores the date but with a time of 00:00:00
Example insert into Contact (mydate) values("2014-10-83") where mydate is of type Date and not DateTime it gets stored as 2014-10-18T00:00:00 instead of just 2014-10-18
I made a patch for the JsonFetchListener so that when fields of type Date are serialized to json they are formated using the db config dateFormat value
Here is the related post https://groups.google.com/d/msg/orient-database/GnID_FKZdL0/sysNt265aDgJ
binary serialization already solve it!