CODEWITHSUNDEEP
androidkotlinunix-timestamp
alexandre9865
alexandre9865

Reputation: 553

Conversion of date and time to unix timestamp - kotlin

In timestamp variable, I want to get the timestampt value with the current hour, minute and second. The currentDataTime gives me the time in this format: 2020-08-28 17:18:02. Currently, the timestamp variable returns me 1598645882634 (the last 3 numbers are the miliseconds) but when I convert it in a online conversor to a Human readable format, it gives me 08/28/2020 @ 8:18pm (UTC). The only one problem is the hour and minute tha is 3 hours different because of my zone. How can I convert the date AND time to timestamp?

object DateTime {
    val currentDataTime: String
        @SuppressLint("SimpleDateFormat")
        get() {
            val dateFormat = SimpleDateFormat("yyyy-MM-dd HH:mm:ss")
            return dateFormat.format(Date())
        }

    val timestamp: String
        get(){
            val formatter: DateFormat = SimpleDateFormat("yyyy-MM-dd HH:mm:ss")
            val date = formatter.parse(currentDataTime) as Date
            return date.time.toString().dropLast(3) //it is returning 
    }
}

Upvotes: 2

Views: 6068

Answers (1)

Oliver O.
Oliver O.

Reputation: 711

A Unix timestamp is defined to be (almost) UTC. It carries no timezone information so it cannot be shifted according to a timezone difference without everything based on it falling apart. (If you'd like to hardwire it anyway, according to your example just add your timezone difference in milliseconds. But read on first.)

Localized time can only be interpreted consistently as long as the proper timezone is attached. It jumps back and forth whenever daylight-savings time starts or ends. If that's not complicated enough, the rules for daylight-savings time may change at any time (and do so around the globe).

Your online converter apparently just took a UTC-based timestamp and displayed it according to your local timezone.

To handle localized date and time values, use the multiplatform date/time library kotlinx-datetime. In the README section Converting an instant to local date and time components you'll find this example:

val currentMoment: Instant = Clock.System.now()
val datetimeInUtc: LocalDateTime = currentMoment.toLocalDateTime(TimeZone.UTC)
val datetimeInSystemZone: LocalDateTime = currentMoment.toLocalDateTime(TimeZone.currentSystemDefault())

There you'll also find elaborate explanations on which type of date and time to use in which scenario.

Upvotes: 4

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