"Eee Mmm Dd Hh:Mm:Ss Zzz Yyyy" Date Format to Java.Sql.Date

How to convert Java String EEE MMM dd HH:mm:ss zzz yyyy date type to Java util.Date yyyy-MM-dd

tl;dr

ZonedDateTime
.parse( 
    "Sat Dec 12 00:00:00 KST 2020" ,
    DateTimeFormatter
    .ofPattern( "EEE MMM dd HH:mm:ss zzz uuuu" )
    .withLocale( Locale.US )
)
.toLocalDate()
.toString()

2020-12-12

Avoid legacy date-time classes

You are using terrible date-time classes that were supplanted years ago by the modern java.time classes. Never use Date, Calendar, or SimpleDateFormat.

You said:

my target date type is Java Date type with format yyyy-MM-dd.

Apparently, you expect Date to hold a date. It does not. The java.util.Date class represents a moment, a date with time-of-day as seen in UTC. The java.sql.Date class pretends to hold only a date, but it too actually contains a date with time-of-day as seen in UTC.

Among the many problems with java.util.Date class is the behavior of its toString method. That method dynamically applies the JVM’s current default time zone while generating text. This anti-feature may contribute to your confusion.

`LocalDate`

Instead you should be using java.time.LocalDate to represent a date-only value without a time-of-day and without a time zone or offset-from-UTC.

`ZonedDateTime`

First use the DateTimeFormatter class to parse your entire input string. This results in a ZonedDateTime object representing a moment as seen through the wall-clock time used by the people of a particular region.

Example code

String input = "Sat Dec 12 00:00:00 KST 2020" ;
DateTimeFormatter f = DateTimeFormatter.ofPattern( "EEE MMM dd HH:mm:ss zzz uuuu" ).withLocale( Locale.US ) ;
ZonedDateTime zdt = ZonedDateTime.parse( input , f ) ;

From that ZonedDateTime object, extract a LocalDate.

LocalDate localDate = zdt.toLocalDate() ;

See this code run live at IdeOne.com.

zdt.toString(): 2020-12-12T00:00+09:00[Asia/Seoul]
ld.toString(): 2020-12-12

About java.time

Table of all date-time types in Java, both modern and legacy

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes. Hibernate 5 & JPA 2.2 support java.time.

Where to obtain the java.time classes?

Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
- Java 9 brought some minor features and fixes.
Java SE 6 and Java SE 7
- Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
- Later versions of Android (26+) bundle implementations of the java.time classes.
- For earlier Android (<26), a process known as API desugaring brings a subset of the java.time functionality not originally built into Android.
  - If the desugaring does not offer what you need, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above) to Android. See How to use ThreeTenABP….

How to compare the datetime of format EEE MMM dd HH:mm:ss zzz yyyy and yyyy-MM-dd hh:mm:sss in java?

If you assume that the timezone of the second date is the same as for the first one then you can just use java.time. It has all parsing tools you need. Any other fixed timezone works as well.

Here is an example:

String a = "Wed Mar 04 03:34:45 GMT+08:00 2020";
String b = "2020-02-04 02:10:58";

ZonedDateTime parsedA;
ZonedDateTime parsedB;

DateTimeFormatter formatterA = DateTimeFormatter.ofPattern("EEE MMM dd HH:mm:ss zzz yyyy");
parsedA = ZonedDateTime.parse(a, formatterA);
DateTimeFormatter formatterB = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
parsedB = LocalDateTime.parse(b, formatterB).atZone(parsedA.getZone());

// What do you want to compare? For example you can tell if a is after b.
System.out.println(parsedA.isAfter(parsedB));

Have a look here if you need another format and need a listing of Pattern Letters and Symbols.

How to parse date to EEE MMM dd HH:mm:ss zzz yyyy format?

Your SimpleDateFormat pattern does not match createdDate. The format should be:

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S");

See the javadoc

Date conversion in MM/DD/YY h:mm:ss a format in java

As per the JavaDoc, D stands for Day in year. You will need to replace DD with dd (day in month).

Y stands for Week year, not year.

In short, this: "DD-MMM-YYYY" needs to be this: "dd-MMM-yyyy".

Trouble formatting date in Java

When debugging parsing issues, if possible, reverse the operation and generate the text you're supposed to be parsing, to verify the parsing rules, i.e. the date format string. This applies to date parsing, JAXB parsing, and any other (de)serializing operation that is bi-directional. It makes finding conversion rule issues a lot easier.

So, let us check the format string in the question, with the shown date value:

ZonedDateTime dateTime = ZonedDateTime.of(2020, 12, 28, 15, 18, 16, 0, ZoneOffset.UTC);
DateTimeFormatter fmt = DateTimeFormatter.ofPattern("EEE MMM dd HH:mm:ss Z YYYY", Locale.US);
System.out.println(dateTime.format(fmt));

Output

Mon Dec 28 15:18:16 +0000 2021

Oops! That doesn't fit the expected output, aka the input we desire to parse:

Mon Dec 28 15:18:16 UTC 2020

So what went wrong?

The year is wrong because it's supposed to be uuuu (year), not YYYY (week-based-year).
The time zone is wrong because Z does support a text representation. Use VV or z instead.

DateTimeFormatter fmt = DateTimeFormatter.ofPattern("EEE MMM dd HH:mm:ss z uuuu", Locale.US);

ZonedDateTime dateTime = ZonedDateTime.parse("Mon Dec 28 15:18:16 UTC 2020", fmt);
System.out.println(dateTime);
System.out.println(dateTime.format(DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss.SSS")));