Kotlin Android / Java String DateTime Format, API21

Question

I want convert string datetime to formatted string. e.g "2018-12-14T09:55:00" to "14.12.2018 09:55" as String => Textview.text

how can I do this with kotlin or java for android ?

Answer 1

Parse it to LocalDateTime then format it:

LocalDateTime localDateTime = LocalDateTime.parse("2018-12-14T09:55:00");
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm");
String output = formatter.format(localDateTime);

If this does not work with api21, you can use:

SimpleDateFormat parser = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
SimpleDateFormat formatter = new SimpleDateFormat("dd.MM.yyyy HH:mm");
String output = formatter.format(parser.parse("2018-12-14T09:55:00"));

or import ThreeTenABP.

Answer 2

Kotlin API levels 26 or greater:

val parsedDate = LocalDateTime.parse("2018-12-14T09:55:00", DateTimeFormatter.ISO_DATE_TIME)
val formattedDate = parsedDate.format(DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm"))

Below API levels 26:

val parser =  SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss")
val formatter = SimpleDateFormat("dd.MM.yyyy HH:mm")
val formattedDate = formatter.format(parser.parse("2018-12-14T09:55:00"))

Answer 3

If you have a date-time that represents a value in a specific time zone but the zone is not encoded in the date-time string itself (eg, "2020-01-29T09:14:32.000Z") and you need to display this in the time zone you have (eg, CDT)

val parsed = ZonedDateTime.parse("2020-01-29T09:14:32.000Z", DateTimeFormatter.ISO_DATE_TIME).withZoneSameInstant(ZoneId.of("CDT"))

That parsed ZoneDateTime will reflect the time zone given. For example, this date would be something like 28 Jan 2020 at 8:32am.

Answer 4

In kotlin u can do this way to format string to date :-

val simpleDateFormat = SimpleDateFormat("yyyy/MM/dd HH:mm:ss",Locale.getDefault())
val date = SimpleDateFormat("yyyy/MM/dd", Locale.getDefault()).format(simpleDateFormat.parse("2022/02/01 14:23:05")!!)

Should import java.text.SimpleDateFormat For SimpleDateFormat Class to work on api 21

Answer 5

java.time

The java.util date-time API and their corresponding parsing/formatting type, SimpleDateFormat are outdated and error-prone. In March 2014, the modern Date-Time API was released as part of the Java 8 standard library which supplanted the legacy date-time API and since then it is strongly recommended to switch to java.time, the modern date-time API.

You do not need a DateTimeFormatter to parse your date-time string

java.time API is based on ISO 8601 and therefore you do not need a DateTimeFormatter to parse a date-time string which is already in ISO 8601 format (e.g. your date-time string, 2018-12-14T09:55:00).

However, your desired output, 14.12.2018 09:55 is not in ISO 8601 standard format and therefore, you need a DateTimeFormatter to get a string in the desired format.

Demo:

class Main {
    public static void main(String[] args) {
        LocalDateTime ldt = LocalDateTime.parse("2018-12-14T09:55:00");
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd.MM.uuuu HH:mm", Locale.ENGLISH);
        String output = ldt.format(formatter);
        System.out.println(output);
    }
}

Output:

14.12.2018 09:55

ONLINE DEMO

Here, you can use y instead of u but I prefer u to y.

Learn more about the modern Date-Time API from Trail: Date Time.

---

^{* If you are working on an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring and How to use ThreeTenABP in Android Project.}

Answer 6

Here is Kotlin One Liner,It will return empty string if input date cannot be parsed.

fun String.getDateInAnotherFormat(inputFormat: String,outputFormat: String):String = SimpleDateFormat(inputFormat, Locale.getDefault()).parse(this)?.let { SimpleDateFormat(outputFormat,Locale.getDefault()).format(it) }?:""

Usage:

var dateStr = "2000-12-08"
dateStr.getDateInAnotherFormat("yyyy-MM-dd","MMM dd YYYY")

Answer 7

Kotlin: Date time format

fun getApiSurveyResponseDateConvertToLocal(date: String?): String? {
        return try {
            val inputFormat = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss", Locale.US)
            val outputFormat = SimpleDateFormat("yyyy-MM-dd", Locale.US)
            val datee = date?.let { inputFormat.parse(it) }
            datee?.let { outputFormat.format(it) }
        } catch (e: ParseException) {
            e.printStackTrace()
            ""
        }
    }

Java: Date time format

public static String getApiSurveyResponseDateConvertToLocal(String date) {

try {
    SimpleDateFormat inputFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss", Locale.US);
    SimpleDateFormat outputFormat = new SimpleDateFormat("yyyy-MM-dd", Locale.US);
   Date datee = inputFormat.parse(date);
    return outputFormat.format(datee);
} catch (ParseException e) {
    e.printStackTrace();
    return "";
}}

Answer 8

Kotlin : Time format converter 24 hrs to 12 hrs

private const val SERVER_TIME_FORMAT = "hh:mm a"
    private const val SERVER_TIME_24HR_FORMAT = "HH:mm"

fun getEmpTimeLineFormat(date: String?): String? {
        val serverFormat = SimpleDateFormat(
            SERVER_TIME_24HR_FORMAT,
            Locale.ENGLISH
        )
        val timelineFormat = SimpleDateFormat(
            SERVER_TIME_FORMAT,
            Locale.ENGLISH
        )
        return try {
            serverFormat.parse(date)?.let { timelineFormat.format(it) }
        } catch (e: ParseException) {
            e.printStackTrace()
            ""
        }
    }