LocalTime

val time = LocalTime(13, 30)
val date = Clock.System.todayAt(TimeZone.currentSystemDefault())
val instant = time.atDate(date).toInstant(TimeZone.currentSystemDefault())
val instantThreeHoursLater = instant.plus(3.hours)
val timeThreeHoursLater = instantThreeHoursLater.toLocalDateTime(TimeZone.currentSystemDefault()).time

import kotlinx.datetime.*
import kotlinx.datetime.format.*
import kotlin.random.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   // Constructing a LocalTime using its constructor
val night = LocalTime(hour = 23, minute = 13, second = 16, nanosecond = 153_200_001)
check(night.hour == 23)
check(night.minute == 13)
check(night.second == 16)
check(night.nanosecond == 153_200_001)

val noon = LocalTime(12, 0)
check(noon.hour == 12)
check(noon.minute == 0)
check(noon.second == 0)
check(noon.nanosecond == 0)

val evening = LocalTime(hour = 18, minute = 31, second = 54)
check(evening.nanosecond == 0) 
   //sampleEnd
}

import kotlinx.datetime.*
import kotlinx.datetime.format.*
import kotlin.random.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   // Representing a LocalTime as the number of seconds, milliseconds, or nanoseconds since the start of the day
val time = LocalTime(hour = 8, minute = 30, second = 15, nanosecond = 123_456_789)
// The number of whole seconds since the start of the day:
val timeAsSecondOfDay = time.toSecondOfDay()
check(timeAsSecondOfDay == 8 * 60 * 60 + 30 * 60 + 15)
// The number of whole milliseconds since the start of the day:
val timeAsMillisecondOfDay = time.toMillisecondOfDay()
check(timeAsMillisecondOfDay == timeAsSecondOfDay * 1_000 + 123)
// The number of nanoseconds since the start of the day:
val timeAsNanosecondOfDay = time.toNanosecondOfDay()
check(timeAsNanosecondOfDay == timeAsMillisecondOfDay * 1_000_000L + 456_789)
// The local time is completely defined by the number of nanoseconds since the start of the day:
val reconstructedTime = LocalTime.fromNanosecondOfDay(timeAsNanosecondOfDay)
check(reconstructedTime == time) 
   //sampleEnd
}

import kotlinx.datetime.*
import kotlinx.datetime.format.*
import kotlin.random.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   // Parsing a LocalTime from a string and formatting it back
val time = LocalTime.parse("08:30:15.1234567")
check(time == LocalTime(8, 30, 15, 123_456_700))
val formatted = time.toString()
check(formatted == "08:30:15.123456700") 
   //sampleEnd
}

import kotlinx.datetime.*
import kotlinx.datetime.format.*
import kotlin.random.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   // Parsing and formatting LocalTime values using a custom format
val customFormat = LocalTime.Format {
    hour(); char(':'); minute(); char(':'); second()
    char(','); secondFraction(fixedLength = 3)
}
val time = LocalTime(8, 30, 15, 123_456_789)
check(time.format(customFormat) == "08:30:15,123")
check(time.format(LocalTime.Formats.ISO) == "08:30:15.123456789") 
   //sampleEnd
}