kotlinlang #kotlinx-datetime

Hi guys! I just joined here after your announcement on the topic. I am working a lot with the JVM time package and miss a lot of stuff in kotlinx-datetime. How and where would you like to get feature requests? Here? Github? The forum discussion?

Vitali Plagov

09/09/2020, 6:55 PM

Hello. I'm trying to use

datetime

library for the following scenario. Can you please help me with it? I need an object with date of now with time at 10:00. Next, I need to change this object by adding one day or by subtracting one day (depending on a certain condition). So, I made the first part:

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var todayAtTen = Clock.System.todayAt(TimeZone.UTC).atTime(hour = 10, minute = 0)

but can't make a second. How can I modify this object by adding one day to it?

Vitali Plagov

09/09/2020, 8:58 PM

Can't understand, how can I subtract one day from a

LocalDate

? There's a

minus()

function that takes

LocalDate

as an argument. But I can't understand, what should I pass in to subtract a particular period of time from it?

flosch

09/12/2020, 9:13 PM

An alternative JVM implementation for Android might be needed.

It should be possible to use

kotlinx-datetime

on Android when targeting 26 and higher, right? I cannot seem to import anything from the

kotlinx.datetime

package. Anything else required for Android that is not mentioned here in the README?

Christian Dräger

10/10/2020, 8:57 PM

Hey I just tryed the kotlinx-datetime and was wandering if it has something like DateTime Formatter and how to use it. Any suggestions? To be more specific I just want to get the current date in a specific format (dd.MM.yyyy) as well as the current time (HHmmss) as strings

Bohdan Yevtushenko

10/15/2020, 1:54 PM

Hello, can I use this library when I have KMP project with IOS as well?

Mateusz Krawczuk

10/22/2020, 10:46 AM

Hi! I'm migrating some logic of my application to multiplatform using kotlinx-datetime, but I have question how can I get first day of the month to compare with other value? This is old kotlin code:

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val init = myDeviceModel.initTimestamp * 1000
            var date = LocalDate().withDayOfMonth(1).toDate()
            if (init > date.time) {
                date = Date(init)
            }

Jan Skrasek

10/25/2020, 7:22 AM

I miss some function which would tell me if year is leap. Did I miss something or it is really missing?

👀 1

Nikky

10/27/2020, 10:26 AM

Clock.System.now().toEpochMilliseconds()

is the equivalent of

System.getCurrentMillis()

👌 1

dgngulcan

11/11/2020, 7:05 PM

now that

Clock

is deprecated, how can I get current date in KMM module?

Darren Bell

11/19/2020, 4:10 PM

Hi. Is there any examples of serialization? For example with @Serializable Thanks

leandro

12/17/2020, 12:01 AM

I (think that I) want to write a test that asserts that a specific amount of Duration has passed, but unsure how to do it. Or, in different words: given an Instant, I would like to simulate running in the future. Do I need some kind of mutable Clock, or should I use timeMark?

leandro

01/19/2021, 4:07 PM

How one can add a month to an Instant? I’m currently doing something like:

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myInstant
      .toLocalDateTime(TimeZone.currentSystemDefault())
      .date.plus(DateTimeUnit.DateBased.MonthBased(1)).atStartOfDayIn(TimeZone.currentSystemDefault()),

Edit: Solved, went with

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.plus(DateTimePeriod(months = 1), TimeZone.currentSystemDefault())

Paul Woitaschek

01/25/2021, 10:02 AM

We are seeing a crash on iOS where ios seems to send and old timezone,

US/Pacific

kotlin.RuntimeException: Unable to acquire the offset at instant 2021-01-20T15:59:38.842138051Z for zone US/Pacific

I don't fully understand what's happening here. Our ios dev says this is related to this issue: https://stackoverflow.com/questions/19819268/convert-ios-localtimezone-to-a-knowntimezone The ios stacktraces aren't present for release frameworks but I think it boils down to this line of code:

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Clock.System.now().toLocalDateTime(TimeZone.currentSystemDefault())

Paul Woitaschek

01/25/2021, 5:45 PM

What we found annoying so far with the DateTimeUnit things is that they throw an exception on duration=0. We have code where we have a dynamic amount of days added:

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loopDate.plus(DateTimeUnit.DateBased.DayBased(fastingDays.size))

Now this throws:

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java.lang.IllegalArgumentException: Unit duration must be positive, but was 0 days.
	at kotlinx.datetime.DateTimeUnit$DateBased$DayBased.<init>(DateTimeUnit.kt:68)

Instead I would prefer to have the function just return the initial date instead of throwing when adding 0 dates. Now we always need to write != 0 checks everywhere and use the initial instance

chi

01/31/2021, 3:41 PM

Any idea how I can derive the first and last day of the week?

why

02/05/2021, 4:49 PM

Hi.. how can I add the library to my android project, I keep getting this error, it can’t find the artifact, any idea?

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Could not resolve all files for configuration ':android:debugRuntimeClasspath'.
   > Could not find org.jetbrains.kotlinx:kotlinx-datetime:0.1.1.
     Searched in the following locations:
       - <https://dl.google.com/dl/android/maven2/org/jetbrains/kotlinx/kotlinx-datetime/0.1.1/kotlinx-datetime-0.1.1.pom>
       - <https://jcenter.bintray.com/org/jetbrains/kotlinx/kotlinx-datetime/0.1.1/kotlinx-datetime-0.1.1.pom>
       - <https://repo.maven.apache.org/maven2/org/jetbrains/kotlinx/kotlinx-datetime/0.1.1/kotlinx-datetime-0.1.1.pom>

cafonsomota

03/27/2021, 1:17 AM

Hello all! I’m using kotlinx-datetime in a project, and I’ve noticed something odd here in my side. I’m converting a

Calendar

object to

LocalDateTime

(kotlinx) by setting the

year

month

, etc. on the constructor; and I’ve noticed that when I call

.toString

it prints something like 2021-03-27T09:00 instead of 2021-03-27T090000Z. What I might be doing wrong?

Paul Woitaschek

03/31/2021, 10:43 AM

What's the timeframe work 0.2.0? https://github.com/Kotlin/kotlinx-datetime/issues/94 This issue causes thousand of crashes for us 😕 Is there a snapshot repository somewhere available for the master versions?

Javier

04/04/2021, 9:32 PM

Is it possible to parse

2014-06-10T16:12:58-0400

Marc Knaup

04/14/2021, 8:32 PM

Does updating to Kotlin 1.5 cause a binary incompatibility with libraries that use
kotlinx-datetime
and are compiled with 1.4? I guess

kotlinx-datetime

isn’t actually compatible with Kotlin 1.5? 😱 Must be the change of

Duration

from

Double

Long

java.lang.NoSuchMethodError: ‘kotlinx.datetime.Instant kotlinx.datetime.Instant.plus-LRDsOJo(long)’

Nikky

04/23/2021, 7:55 AM

does kotlinx-datetime have a way to get a date from the weeknumber ? i found a workaround using

java.util.Calendar

but i am not happy about it

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fun getMondayOfWeek(year: Int, week: Int): LocalDate {
    val cal = Calendar.getInstance()
    cal.set(Calendar.WEEK_OF_YEAR, week)
    cal.set(Calendar.YEAR, year)
    cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY)
    return cal.time.toInstant().toKotlinInstant().toLocalDateTime(systemTZ).date
}

is there a better way ?

KamilH

04/23/2021, 8:41 AM

Can we expect a support to custom formats of the date? I saw this issue: https://github.com/Kotlin/kotlinx-datetime/issues/58 but no comments are there so I’m curious if such a feature is planned for any of the near releases

dave08

05/10/2021, 3:10 PM

Hi! Wouldn't it be nice to have the Clock interface declared as a

fun interface

? That would allow very simple overriding of

now()

in unit tests... unless there are plans to add other functions to it?

Marc Knaup

05/25/2021, 2:34 PM

If this is a deliberate change in Kotlin (expect enums no longer exhaustive) then please don’t use

expect enum

kotlinx-datetime

😕 https://github.com/Kotlin/kotlinx-datetime/issues/96

Marc Knaup

05/25/2021, 3:25 PM

Inconsistent:

kotlinx-datetime

Instant

LocalDate

, etc. • uses ISO-8601 for `toString()`/`parse()` • provides serializer

kotlin.time

Duration

OTOH • uses human-readable output for

toString()

, returns ISO-8601 for

toIsoString()

, and has no

parse()

• has no serializer Still two different date/time worlds in Kotlin and usage is confusing and error-prone.

😔 1

LastExceed

05/29/2021, 7:07 PM

this jb blog post says

The default serializer is based on an ISO 8601 string representation of a type and uses `toString()`/`parse()` to serialize and deserialize values

the linked wikipedia article lists

2021-05-29T17:42:42+00:00

as an example string so why do i get an exception here ? Slack Conversation

Nikky

06/10/2021, 12:41 PM

seems like on JS the toString() function adds 3 digits but on JVM it does 8 to the fractional seconds is there a way to configure it to be consistent ?

iamthevoid

06/25/2021, 7:18 AM

I try to add value to instant. When i do this i get error [1]. But it looks strange because looks like method

plus

defined in

Instant.kt

[2]. How i can handle this problem?