How to format timestamp in outgoing JSON

Question

I've been playing with Go recently and it's awesome. The thing I can't seem to figure out (after looking through documentation and blog posts) is how to get the `time.Time` type to format into whatever format I'd like when it's encoded by `json.NewEncoder.Encode` Here's a minimal Code example: ``` package main type Document struct { Name string Content string Stamp time.Time Author string } func sendResponse(data interface{}, w http.ResponseWriter, r * http.Request){ _, err := json.Marshal(data) j := json.NewEncoder(w) if err == nil { encodedErr := j.Encode(data) if encodedErr != nil{ //code snipped } }else{ //code snipped } } func main() { http.HandleFunc("/document", control.HandleDocuments) http.ListenAndServe("localhost:4000", nil) } func HandleDocuments(w http.ResponseWriter,r *http.Request) { w.Header().Set("Content-Type", "application/json") w.Header().Set("Access-Control-Allow-Origin", "*") switch r.Method { case "GET": //logic snipped testDoc := model.Document{"Meeting Notes"…

Accepted Answer

What you can do is, wrap time.Time as your own custom type, and make it implement the `Marshaler` interface:

```
type Marshaler interface {
    MarshalJSON() ([]byte, error)
}
```

So what you'd do is something like:

```
type JSONTime time.Time

func (t JSONTime)MarshalJSON() ([]byte, error) {
    //do your serializing here
    stamp := fmt.Sprintf("\"%s\"", time.Time(t).Format("Mon Jan _2"))
    return []byte(stamp), nil
}
```

and make document:

```
type Document struct {
    Name        string
    Content     string
    Stamp       JSONTime
    Author      string
}
```

and have your intialization look like:

```
 testDoc := model.Document{"Meeting Notes", "These are some notes", JSONTime(time.Now()), "Bacon"}    
```

And that's about it. If you want unmarshaling, there is the `Unmarshaler` interface too.

How to format timestamp in outgoing JSON

Solution

Problem