Find number of seconds elapsed since Unix epoch in Kotlin

This article explores different ways to find the number of seconds elapsed since the Unix epoch in Kotlin. The Unix epoch (or Unix time or Epoch time or Posix time) is the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC.

1. Using `System.currentTimeMillis()` function

The simplest way is probably using the System.currentTimeMillis() function that returns the difference between the current time and Unix epoch in “milliseconds”. This is demonstrated below:

fun main() {

val ms = System.currentTimeMillis()

println(ms)

}

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Output (will vary):

1640882619680

To get the number of “seconds” elapsed since the Unix epoch, we can simply divide the return value of the System.currentTimeMillis() function by 1000.

fun main() {

val timestamp = System.currentTimeMillis() / 1000

println(timestamp)

}

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Output (will vary):

1640882633

2. Using `Instant.toEpochMilli()` function

The java.time.Instant class represents an instantaneous point on the time-line. We can get the current instant using the Instant.now() function and convert this instant to the number of seconds from the Unix epoch with epochSecond.

import java.time.Instant

fun main() {

val timestamp = Instant.now().epochSecond

println(timestamp)

}

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Output (will vary):

1640882923

Additionally, we can convert the current instant to the number of milliseconds from the epoch using the toEpochMilli() function.

import java.time.Instant

fun main() {

val ms = Instant.now().toEpochMilli()

println(ms)

}

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Output (will vary):

1640882923772

That’s all about finding the number of seconds elapsed since the Unix epoch in Kotlin.

Find number of seconds elapsed since Unix epoch in Kotlin

1. Using System.currentTimeMillis() function

2. Using Instant.toEpochMilli() function

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1. Using `System.currentTimeMillis()` function

2. Using `Instant.toEpochMilli()` function