SimpleDateFormat warning To get local formatting use getDateInstance(), getDateTimeInstance(), or getTimeInstance(),

Question

Do i need to be worried about this warning? What if I ignore the warning?
What does this warning mean:
To get local formatting use getDateInstance(),

Answer 1

Same for kotlin

        //example long 1372339860 
        fun getDateTime(unixSeconds: Long): String {
         val date = java.util.Date(unixSeconds * 1000L)

         val simpleDateFormat = SimpleDateFormat("yyyy-MM-dd HH:mm:ss z", Locale.getDefault())
         return simpleDateFormat.format(date)
        }

Call like this getDateTime(1372339860)

It will return 27.6.2013 15:31:00 GMT +2 The GMT+2 because I'm in Germany and we have summer time. You can use Locale.US as well.