Currently, I've used the postman to make a request to standard Saleforce API.
At the Date field I inputted year only.
As I expected, that should be inserted fail for that case. But actually, the record inserted successful. And I've taken a look at the date field, it populated the first day of inputted year.
That's so strange. As I known that salesforce API allow only the input date with format: yyyy-MM-dd. I tried to research why but no luck. Could anyone give me an explanation or related document about this?? Thanks in advance!