Simple data format kotlin

Time Formatting / Parsing in Kotlin

Kotlin provides a powerful set of tools for formatting and parsing date and time values. Here we’ll explore some of the ways you can format and parse dates and times in Kotlin.

Introduction

When working with date and time values, it’s important to be able to convert between different formats. For example, you might need to convert a date from one format to another, or parse a string value into a Date object. Kotlin provides a number of built-in methods for this purpose, as well as a powerful set of classes from the java.time package that can help you format and parse dates and times.

Formatting Dates and Times

The simplest way to format a date or time is to use the built-in functions provided in the Kotlin Standard Library. These functions are useful for basic formatting tasks, such as displaying a date in a specific format.

For example, the following code formats a Date object as a simple string in the format yyyy-MM-dd:

val date = Date() val formattedDate = date.format("yyyy-MM-dd") println(formattedDate) // Outputs: 2020-04-09 

If you need to use a more complex format, you can use the java.time package to create a DateTimeFormatter object with the desired format. The following code creates a formatter that displays the date in the format yyyy-MM-dd HH:mm:ss:

val formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss") val formattedDate = date.format(formatter) println(formattedDate) // Outputs: 2020-04-09 12:45:30 

Parsing Dates and Times

Kotlin also provides a number of methods for parsing date and time values. The simplest way to parse a date is to use the built-in functions provided in the Kotlin Standard Library.

For example, the following code parses a string containing a date in the format yyyy-MM-dd and produces a Date object representing that date:

val dateString = "2020-04-09" val date = dateString.parse("yyyy-MM-dd") println(date) // Outputs: Tue Apr 09 00:00:00 EST 2020 

If you need to parse a more complex format, you can use the java.time package to create a DateTimeFormatter object with the desired format. The following code creates a formatter that parses a string containing a date in the format yyyy-MM-dd HH:mm:ss:

val formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss") val dateString = "2020-04-09 12:45:30" val date = dateString.parse(formatter) println(date) // Outputs: Tue Apr 09 12:45:30 EST 2020 

Conclusion

Kotlin provides a powerful set of tools for formatting and parsing date and time values. The built-in functions in the Kotlin Standard Library are useful for basic formatting and parsing tasks, while the java.time package provides more advanced features for complex formats. With these tools, you can easily format and parse dates and times in Kotlin.

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How to format in kotlin date in string or timestamp to my preferred format?

Formatting a date in Android can be a complex task, especially when working with different time zones and locales. In Kotlin, you can use the SimpleDateFormat class to format a date and time into a string representation, or parse a string into a Date object. The SimpleDateFormat class provides a variety of patterns that you can use to format the date and time, but it can be challenging to get the formatting just right. This tutorial will guide you through the process of formatting a date in Kotlin and provide you with solutions to some common problems you may encounter along the way.

Method 1: SimpleDateFormat Class

To format a date in Kotlin using the SimpleDateFormat class, you can follow these steps:

1. Create an instance of SimpleDateFormat class by passing your desired date format as a string to the constructor.

val dateFormat = SimpleDateFormat("dd/MM/yyyy")

val date = Date() // current date and time

1. Call the format() method on your SimpleDateFormat object, passing in your Date object as a parameter.

val formattedDate = dateFormat.format(date)

Here are some additional examples:

// Format a timestamp to a string date val timestamp = 1629360000000 // 2021-08-19T00:00:00Z val date = Date(timestamp) val dateFormat = SimpleDateFormat("dd/MM/yyyy") val formattedDate = dateFormat.format(date) // "19/08/2021" // Format a string date to a different format val dateString = "19/08/2021" val dateFormat = SimpleDateFormat("dd/MM/yyyy") val date = dateFormat.parse(dateString) val newDateFormat = SimpleDateFormat("yyyy-MM-dd") val formattedDate = newDateFormat.format(date) // "2021-08-19"

That’s it! With these steps, you can easily format dates in Kotlin using the SimpleDateFormat class.

Method 2: Using the DateTimeFormatter Class

To format a date in Kotlin using the DateTimeFormatter class, you can follow these steps:

1. Create a LocalDateTime object with the desired date and time.
2. Define the pattern for the date format you want to use.
3. Create a DateTimeFormatter object using the pattern.
4. Format the LocalDateTime object using the DateTimeFormatter object.

Here is an example code that formats a date in the format «dd/MM/yyyy HH:mm:ss»:

import java.time.LocalDateTime import java.time.format.DateTimeFormatter fun formatDate(date: LocalDateTime): String  val pattern = "dd/MM/yyyy HH:mm:ss" val formatter = DateTimeFormatter.ofPattern(pattern) return date.format(formatter) > // Example usage val now = LocalDateTime.now() val formattedDate = formatDate(now) println(formattedDate) // Output: "25/08/2021 14:30:45"

In the above code, the formatDate function takes a LocalDateTime object as input and returns a formatted string using the DateTimeFormatter class.

You can customize the date format by changing the pattern variable to your desired format. For example, to format the date as «yyyy-MM-dd», you can change the pattern to «yyyy-MM-dd» .

Method 3: Using the Date class

To format a date in Kotlin using the Date class, you can use the SimpleDateFormat class. Here’s an example:

import java.text.SimpleDateFormat import java.util.Date fun formatDate(date: Date, format: String): String  val formatter = SimpleDateFormat(format) return formatter.format(date) > // Usage: val date = Date() val formattedDate = formatDate(date, "dd/MM/yyyy") println(formattedDate) // Output: 12/09/2021

In the example above, we define a function formatDate that takes a Date object and a format string as arguments, and returns a formatted date string. The SimpleDateFormat class is used to format the date according to the specified format.

The format string can contain various placeholders to represent different parts of the date, such as dd for day of the month, MM for month, yyyy for year, HH for hour, mm for minute, ss for second, and so on.

Here are some examples of format strings and their corresponding output:

val date = Date() formatDate(date, "dd/MM/yyyy") // Output: 12/09/2021 formatDate(date, "yyyy-MM-dd") // Output: 2021-09-12 formatDate(date, "EEE, MMM d, ''yy") // Output: Sun, Sep 12, '21 formatDate(date, "h:mm a") // Output: 10:30 PM

Note that the SimpleDateFormat class is not thread-safe, so it’s recommended to create a new instance for each thread or synchronize access to a shared instance.

Method 4: Using the Calendar class

To format a date in Kotlin using the Calendar class, you can follow these steps:

val calendar = Calendar.getInstance() calendar.timeInMillis = timestampInMillis

val dateFormat = SimpleDateFormat("dd/MM/yyyy HH:mm:ss", Locale.getDefault())

val formattedDate = dateFormat.format(calendar.time)

Here is the complete code example:

val calendar = Calendar.getInstance() calendar.timeInMillis = timestampInMillis val dateFormat = SimpleDateFormat("dd/MM/yyyy HH:mm:ss", Locale.getDefault()) val formattedDate = dateFormat.format(calendar.time)

In this example, timestampInMillis is the timestamp in milliseconds that you want to format. The dateFormat variable defines the format of the output date, which in this case is «dd/MM/yyyy HH:mm:ss». The Locale.getDefault() method is used to get the default locale of the device.

This code will output the formatted date as a string in the format «dd/MM/yyyy HH:mm:ss».

Note that the Calendar class is a bit outdated and there are newer and more efficient ways to format dates in Kotlin, such as using the Java 8 DateTime API or the Kotlin DateTime library.

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How To Format Date in Kotlin — All in One Solution

Are you worrying? How to format timestamp to String date? here you can find the complete solution in one place.

Here we have created a generic Method that you can use where ever you require.

public fun getDateFormattedFromTimeStamp(timestamp: Long, format: String): String

Usage: Time Stamp To Simple String Date Format

getDateFormattedFromTimeStamp(Calendar.getInstance().timeInMillis, "yyyy, MMM dd") output: // 2022, Sep 03

An explanation for other Date Formats

Year:

“ yyyy ” → 4-digit Year (eg. 2022 )
“ yy ” → 2-digit Year (eg. 22 )

Month:

“ MM ” → 2-digit Month (eg. 01 )
“ MMM ” → 3- character Month (eg. Jan )
“ MMMM ” → Full characters Month (eg. January )

Day:

“ dd ” or “ d ” → Day in a month (eg. 19 )

“ DD ” or “ D ” → Day in Year (eg. 262 )

val timestamp = 1663584353488 DateUtil.getDateFormattedFromTimeStamp(timestamp, "yyyy-MMM-dd") // 2022-Sep-19 DateUtil.getDateFormattedFromTimeStamp(timestamp, "yyyy, MMM dd") // 2022, Sep 19 DateUtil.getDateFormattedFromTimeStamp(timestamp, "yyyy/MMM/dd") // 2022/Sep/19 DateUtil.getDateFormattedFromTimeStamp(timestamp, "yyyy/MM/dd") // 2022/09/19 DateUtil.getDateFormattedFromTimeStamp(timestamp, "dd MMM, yy") // 19 Sep, 22 DateUtil.getDateFormattedFromTimeStamp(timestamp, "dd, MMM yy") // 19, Sep 22 DateUtil.getDateFormattedFromTimeStamp(timestamp, "dd, MMM yyyy") // 19, Sep 2022 DateUtil.getDateFormattedFromTimeStamp(timestamp, "dd MMM, yyyy") // 19 Sep, 2022 DateUtil.getDateFormattedFromTimeStamp(timestamp, "dd MM, yyyy") // 19 09, 2022 DateUtil.getDateFormattedFromTimeStamp(timestamp, "DD MM, yyyy") // 262 09, 2022 DateUtil.getDateFormattedFromTimeStamp(timestamp, "dd MMMM, yyyy") // 19 September, 2022

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