@ Robert
The CSV correctly imports using the old anniversary/birthday method which did not store years, only month and day. The CSV is undergoing a complete rewrite and should be released in March.
The values are actually stored twice in the database. Once as arrays in the main entry table and the other as actual data stored in separate tables based on the type of data being stored. Those tables are easily identified as they have “connections” in the name.
Why is this stored twice? For performance. The stored arrays can sort of be considered as cached objects. When displaying entry data, the cached objects are used instead of creating multiple queries to the database for each entry being displayed. The actual data is not used unless sorting by those values, doing geo location type queries [a feature not yet exposed] and adding/editing an entry.
I hope that makes sense.