Java Convert Timestamp to Date

The conversion of a Timestamp to a Date in Java is considered a simple and straightforward process. The Timestamp can be utilized for representing a particular moment of time which is majorly used for operations related to database. Whereas, a Date can be utilized for representing a particular point in time, which can be either date or time of day.

The conversion of Timestamp to Date can be carried out in several ways. Let's understand about them in detail in the following paragraphs.

Approach: Using Constructors

In Java, converting a Timestamp to a Date using constructors involves leveraging the java.util.Date class's constructor that accepts a long value representing milliseconds since the epoch. The Timestamp class, found in the java.sql package, extends java.util.Date, making this conversion straightforward. To perform the conversion, you can extract the milliseconds from the Timestamp using its getTime() method and then pass that value to the Date constructor.

Remember that when converting a Timestamp type to a Date using constructors, the resulting Date object will lose the nanosecond precision that is present in the Timestamp object, as Date only maintains precision up to milliseconds. If you require nanosecond precision, alternative approaches, such as using java.time classes introduced in Java 8, may be more suitable.

Let's see an example Java program that implements the above-mentioned approach.

Filename: TimestampToDate.java

Output:

 Original Timestamp: 2024-03-29 22:26:12.454 Converted Date: Fri Mar 29 22:26:12 IST 2024 

Approach: Using Date Reference

Converting a Timestamp to a Date using a Date reference in Java involves creating a Date object and setting its time based on the Timestamp value. The approach is useful when we want to reuse an existing Date object rather than creating a new one.

To achieve this conversion, we start by creating a Timestamp object representing the time you want to convert, which could be the current time or a specific time from a database or other source. Next, we create a Date object that you want to modify or set using the Timestamp value.

This Date object can be instantiated using the default constructor, which initializes it with the current time. Finally, you use the setTime() method of the Date class, passing in the milliseconds value of the Timestamp, to set the time of the Date object.

Let's see an example Java program that implements the above-mentioned approach.

Filename: TimestampToDate1.java

Output:

 Original Timestamp: 2024-03-29 22:35:44.703 Converted Date: Fri Mar 29 22:35:44 IST 2024 

Approach: Using Calendar Class

Converting a Timestamp to a Date using the Calendar class in Java involves a multi-step process. First, we create a Calendar instance and set its time using the milliseconds value of the Timestamp. Then, we extract the year, month, day, hour, minute, second, and millisecond components from the Calendar instance and use them to construct a new Date object.

This approach is useful when we need to perform date manipulations or extract specific components of the date. However, it is important to note that the Calendar class is considered somewhat outdated, and it is recommended to use the java.time API introduced in Java 8 for date and time operations.

Let's see an example Java program that implements the above-mentioned approach.

Filename: TimestampToDate2.java

Output:

 Original Timestamp: 2024-03-31 01:22:20.667 Converted Date: Sun Mar 31 01:22:20 IST 2024 

It is all the required information and explanation regarding the conversion of Timestamp to Date in Java.