Java LocalDate atStartOfDay( ) Method with Example

In this article we are going to see the use of Java LocalDate class atStartOfDay( ) method with suitable examples.

Java LocalDate atStartOfDay( ) Method with Example

This java.time.LocalDate.atStartOfDay() method is used to combine the date with the time of midnight to create a LocalDate Time. It returns the local date’s time of midnight at the start of the day.

Syntax:

public LocalDateTime atStartOfDay()

Let’s see the use of atStartOfDay( ) method with 2 different format.

Method-1: without parameters

Approach:

  1. Create an object of LocalDate class which will hold the parsed date.
  2. By using that LocalDate class object call atStartOfDay() method and assign the result to an object of LocaldateTime class.
  3. Then print the final LocalDateTime as result.

Program:

import java.time.LocalDate;
import java.time.LocalDateTime;
public class Main
{
    public static void main(String[] args)
    {
    //Create an object of LocalDate class and assign a date to it
    //here it parses the local date
    LocalDate date = LocalDate.parse("2022-05-10");
    System.out.println("Specific date: "+date);  
    //Create an object of LocalDateTime
    //call the atStartOfDay() method by using object of LocalDate class
    LocalDateTime startTime = date.atStartOfDay();
    System.out.println("Start Time: "+startTime);  
   }
}
Output:

Specific date: 2022-05-10
Start Time: 2022-05-10T00:00

Method-2: with parameters

Approach:

  1. Create an object of LocalDate class which will hold the parsed date.
  2. By using that LocalDate class object call atStartOfDay() method and by passing ZoneId.systemDefault() as parameter and assign the result to an object of ZoneddateTime class.
  3. Here we pass the ZoneId which is already defined by system so that it will take a particular zone and represent that zone’s start time.
  4. Then print the final ZonedDateTime as result.

Program:

import java.time.*;
public class Main
{
    public static void main(String[] args)
    {
    //Create an object of LocalDate class and assign a date to it
    //here it parses the local date
    LocalDate date = LocalDate.parse("2022-05-10");
    System.out.println("Specific date: "+date);  
    //Create an object of LocalDateTime
    //call atStartOfDay() method by passing the ZoneId.systemDefault() as parameter
    ZonedDateTime startTime = date.atStartOfDay(ZoneId.systemDefault());
    System.out.println("Start Time: "+startTime);  
   }
}
Output:

Specific date: 2022-05-10
Start Time: 2022-05-10T00:00Z[GMT]

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