Format of date display: Data Out API vs. Datastructure API

[geofranzi]

Currently the Data Out API prints date values in a different schema as the data structure API

• unify it?
• find applications using / rely on current writing if we change

Data Out API: 9998-12-31T21:59:59
Struture API: "placeholder": "12/31/9998 9:59:59 PM",

[DavidBlaa]

please test

[DavidBlaa]

the missing value placeholder -> 12/31/9998 9:59:59 PM is needed because its the datetime format of the database.
every outcome now has the missing values instead of the datatype values.

12/31/9998 9:59:59 PM -> na