A simple question, how to convert the timestamp to Y in this case?

The above is the output timestamp in AJAX. I don’t know how to do it, so I tried to convert it in PHP

But why can’t I rotate like this in the model or C? When output, this array becomes this field, and other fields are lost

I found out from the answer of an expert above that you can use the mysql statement to convert the addtime into time format in the linked list. But in TP, if you add that kind of conversion statement after the field field, will an error be reported? Does anyone know how to write without getting an error?

I know I am a bit mentally retarded with this question, so I humbly seek advice from an expert, thank you