How to format in Kotlin date in string or timestamp to my preferred format?

Try this code to get dayOfWeek and month name

Code

To String Date

Method

fun getAbbreviatedFromDateTime(dateTime: String, dateFormat: String, field: String): String? {
    val input = SimpleDateFormat(dateFormat)
    val output = SimpleDateFormat(field)
    try {
        val getAbbreviate = input.parse(dateTime)    // parse input
        return output.format(getAbbreviate)    // format output
    } catch (e: ParseException) {
        e.printStackTrace()
    }

    return null
}

*How to use

val monthName=getAbbreviatedFromDateTime("2019-08-07 09:00:00","yyyy-MM-dd HH:mm:ss","MMMM")
    println("monthName--"+monthName)

    val dayOfWeek=getAbbreviatedFromDateTime("2019-08-07 09:00:00","yyyy-MM-dd HH:mm:ss","EEEE")
    println("dayOfWeek--"+dayOfWeek)

To Timemillis

Methods

 fun convertStringToCalendar( timeMillis: Long) {
    //get calendar instance
    val calendarDate = Calendar.getInstance()
    calendarDate.timeInMillis = timeMillis
    val month=getAbbreviatedFromDateTime(calendarDate,"MMMM");
    val day=getAbbreviatedFromDateTime(calendarDate,"EEEE");
    Log.d("parseTesting", month)// prints August
    Log.d("parseTesting",day)// prints Wednesday
}


fun getAbbreviatedFromDateTime(dateTime: Calendar, field: String): String? {
    val output = SimpleDateFormat(field)
    try {
        return output.format(dateTime.time)    // format output
    } catch (e: Exception) {
        e.printStackTrace()
    }

    return null
}

Use

 val timestamp = "1565209665".toLong()

    convertStringToCalendar(timestamp)

First API format:

val firstApiFormat = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")
val date = LocalDate.parse("2019-08-07 09:00:00" , firstApiFormat)

Log.d("parseTesting", date.dayOfWeek.toString()) // prints Wednesday
Log.d("parseTesting", date.month.toString()) // prints August

Second API format:

val secondApiFormat = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss'Z'")
val timestamp = 1565209665.toLong() // timestamp in Long


val timestampAsDateString = java.time.format.DateTimeFormatter.ISO_INSTANT
            .format(java.time.Instant.ofEpochSecond(timestamp))

Log.d("parseTesting", timestampAsDateString) // prints 2019-08-07T20:27:45Z


val date = LocalDate.parse(timestampAsDateString, secondApiFormat)

Log.d("parseTesting", date.dayOfWeek.toString()) // prints Wednesday
Log.d("parseTesting", date.month.toString()) // prints August

This is really simple

val dateFormated = SimpleDateFormat("dd/MM/yyyy").format(trans.created_date.toDate())

I hope this works for everybody, thanks to https://www.datetimeformatter.com/how-to-format-date-time-in-kotlin/