How to convert JSON string to struct

I have start working in golang, I am trying to parse JSON string to struct but its not working.

JSON String:

dailies":[{"userAccessToken":"acessToken","uploadStartTimeInSeconds":1499744832,"uploadEndTimeInSeconds":1499744832,"callbackURL":"callbackurl"}]}

type pingDataFormat struct {
    userAccessToken          string
    uploadStartTimeInSeconds int
    uploadEndTimeInSeconds   int
    callbackURL              string 
}

Below is code which convert JSON String to structs

pingJSON := make(map[string][]pingDataFormat)

err := json.Unmarshal([]byte(pingData), &pingJSON)

if err != nil {
    panic(err)
}

fmt.Printf("\n\n json object:::: %v", pingJSON)

output is:

json object:::: map[dailies:[{ 0 0 }]]

Here "dailies" dont have data, So do i following right approach to parse and how to get data after parse?