That works, the datestrings get parsed correctly. Thank you very much, you have really been a great help so far.
Now there is one more thing to do to write the data to the database. We can't use the bulk upsert for some reasons related to the data source from which the REST API retrieves the data. Instead of using the ID of the records we need to use 2 fields for filtering, AdrNr and AnsNr.
Now when I try to insert/update in a loop all the records from the REST call into the database, I need an index for the data array.
If I specify an exact index in the data array, e.g. "0" or "17", then the insert/update works. When I don't use the specific index of a single data record, all the inserted values are null.
But what exactly do I need to specify as index so that all data records in the array can be inserted correctly in the loop?