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SimpleDate format is not converting time to IST

I am trying to get time (HH:MM) from below code in IST format but it still display UTC date, time.
Please help.
public static void main (String args[]) throws ParseException {
String date = "2021-07-05T14:17:00.000Z";
Calendar now = Calendar.getInstance();
TimeZone timeZone = now.getTimeZone();
String timezoneID = timeZone.getID();
// Convert to System format from UTC
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
Date actualDate = format1.parse(date);
format1.setTimeZone(TimeZone.getTimeZone(timezoneID));
String date1 = format1.format(actualDate);
String time = date1.substring(11, 16);
String timezoneValue = TimeZone.getTimeZone(timezoneID).getDisplayName(false, TimeZone.SHORT);
String finalTime = time + " " + timezoneValue;
System.out.print(finalTime);
}

java.time
I strongly recommend that you use java.time, the modern Java date and time API, for your date and time work. Then your task becomes pretty simple. Rather than a formatter for your input format I want to define a formatter for your desired time format:
private static final DateTimeFormatter TIME_FORMATTER
= DateTimeFormatter.ofPattern("HH:mm zzz", Locale.ENGLISH);
Now the operation goes in these few lines:
String date = "2021-07-05T14:17:00.000Z";
String finalTime = Instant.parse(date)
.atZone(ZoneId.systemDefault())
.format(TIME_FORMATTER);
System.out.println(finalTime);
Output when I ran in Europe/Dublin time zone:
15:17 IST
Here IST is for Irish Summer Time. IST has several meanings, and I wasn’t sure which one you intended. Also many of the other popular time zone abbreviations are ambiguous. IST may also mean Israel Standard Time, but not here, since Israel uses Israel Daylight Time or IDT at this time of year. One other interpretation is India Standard Time used in India and Sri Lanka, So let’s try running the code in Asia/Kolkata time zone.
19:47 IST
I am exploiting the fact that your string is in ISO 8601 format, the format that the classes of java.time parse and also print as their default, that is, without any specified formatter.
What went wrong in your code?
Your bug is here:
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
You must never hardcode Z as a literal in your format pattern, which is what you are doing when enclosing it in single quotes. The Z is a UTC offset and needs to be parsed as such so that Java knows that your date and time are in UTC (which is what Z means). When you hardcode the Z, SimpleDateFormat understands the date and time to be in the default time zone of the JVM. So when afterward you try to convert into that time zone, the time of day is not changed. You’re converting into the time zone you already had. It’s a no-op.
Links
Oracle tutorial: Date Time explaining how to use java.time.
Wikipedia article: ISO 8601
Time Zone Abbreviations – Worldwide List

You are parsing the date using your default TimeZone, not UTC.
You never called format1.setTimeZone before parsing. A DateFormat uses the default timezone unless you set it to something else.
Let’s look at each line of your code:
Calendar now = Calendar.getInstance();
TimeZone timeZone = now.getTimeZone();
That is getting the default TimeZone. You don’t need a Calendar object for that; just call TimeZone.getDefault().
String timezoneID = timeZone.getID();
There is no reason to call that. You already have a TimeZone object. Converting it to a string ID and back to a TimeZone is a pointless round-trip operation. So, you should remove all uses of timezoneID.
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
That is the problem. The DateFormat doesn’t treat the 'Z' as anything special; it’s just a literal character which the DateFormat knows not to parse.
You need to actually tell the DateFormat that it’s parsing a UTC time:
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
TimeZone utc = TimeZone.getTimeZone(ZoneOffset.UTC);
format1.setTimeZone(utc);
Date actualDate = format1.parse(date);
Instead of cutting out pieces of a formatted string, make a new DateFormat that does exactly what you want:
DateFormat timeFormat = new SimpleDateFormat("HH:mm z");
String finalTime = timeFormat.format(actualDate);
Since a SimpleDateFormat always uses the default TimeZone when it is created, there is no need to call this format object’s setTimeZone method.
I should mention that the java.time and java.time.format packages are much better for working with dates and times:
String date = "2021-07-05T14:17:00.000Z";
Instant instant = Instant.parse(date);
ZonedDateTime utcDateTime = instant.atZone(ZoneOffset.UTC);
ZonedDateTime istDateTime =
utcDateTime.withZoneSameInstant(ZoneId.systemDefault());
String finalTime = String.format("%tR %<tZ", istDateTime);
// Or:
// String finalTime = istDateTime.toLocalTime() + " "
// + itsDateTime.getZone().getDisplayName(
// TextStyle.SHORT, Locale.getDefault());

format1.setTimeZone(TimeZone.getTimeZone("Asia/Kolkata"));
is what you need since the 3-letter zone names are really deprecated. Plus:
String timezoneValue = format1.getTimeZone().getDisplayName(false, TimeZone.SHORT);

The method Calendar.getInstance() gets a calendar using the default time zone and locale - UTC±00:00.
Use "IST" instead of timeZone.getID().
Exemple:
String date="2021-07-05T14:17:00.000Z";
Calendar now = Calendar.getInstance();
TimeZone timeZone = now.getTimeZone();
String timezoneID = "IST"; // <<<<<
// Convert to System format from UTC
DateFormat format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
Date actualDate = format1.parse(date);
format1.setTimeZone(TimeZone.getTimeZone(timezoneID));
String date1 = format1.format(actualDate);
String time = date1.substring(11, 16);
String timezoneValue = TimeZone.getTimeZone(timezoneID).getDisplayName(false, TimeZone.SHORT);
String finalTime = time + " " + timezoneValue;
System.out.print(finalTime);

Convert milliseconds to timestamp with UTC

I'm trying to convert milliseconds to Timestamp with timezone UTC but it doesn't work as is expected because it convert to my localdatetime.
I have tried following. While debugging the code I have found that when execute this: new DateTime(eventDate) it is working properly because it's value is 10:34:18.721 but later new Timestamp() change it to localdatetime.
long eventDate = 1566297258721L;
DateTimeZone.setDefault(DateTimeZone.UTC);
Timestamp timestamp = new Timestamp(new DateTime(eventDate).getMillis());
I expect to output as:2019-08-20 10:34:18.721 but actual output is: 2019-08-20 12:34:18.721

You can use java.time package of Java 8 and later:
ZonedDateTime zonedDateTime = Instant.ofEpochMilli(1566817891743L).atZone(ZoneOffset.UTC);

I don't understand why you are creating a new DateTime and then get the milliseconds from there, if you already have the milliseconds in the beginning.
Maybe I'm misunderstanding your problem. The milliseconds have nothing to do with the timezone. The timezone is used to compare the same moment in 2 different places and get the respective date. Here are my solutions
If you want a timestamp from milliseconds:
long eventDate = 1566297258721L;
Timestamp time=new Timestamp(eventDate);
System.out.println(time);
The result would be 2019-08-20 10:34:18.721 , also the wished SQL format
If you want to convert a moment from a Timezone to another:
You will get the moment in your actual timezone and transform it in a different one in order to see e.g. what time it was in an other country
long eventDate = 1566297258721L;
Calendar calendar = Calendar.getInstance();
calendar.setTime(eventDate);
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
dateFormat.format(calendar.getTime());
I hope those snippets could be useful. Happy Programming!

You can try the following,
long eventDate = 1566297258721L;
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss z", Locale.US);
simpleDateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
String stringDate = simpleDateFormat.format(new Date(eventDate));
System.out.println(stringDate);
It gives me the following output.
2019-08-20 10:34:18 UTC

SimpleDateFormat sets current day for parsed date

Is there any way to use the following simpleDateFormat:
final SimpleDateFormat simpleDateFormatHour = new SimpleDateFormat("HH:mm:ss z");
and when invoking:
simpleDateFormat.parse("12:32:21 JST");
to return current date on the Date object?
For these example, it will return:
Thu Jan 01 05:32:21 EET 1970
and not:
<<today>> 05:32:21 EET <<currentYear>>
as I need.

No, SimpleDateFormat needs explicity the date in the input string. If you're using Java 8, you can go with a LocalDateTime:
LocalDateTime localDateTime = LocalDate.now().atTime(5, 32, 21);
If you want to include a time-zone, you can use ZonedDateTime.

Construct another SimpleDateFormat to print today's date:
String today = new SimpleDateFormat("yyyy/MM/dd").print(new Date());
(Be careful here: you might want to set the time zone on the SimpleDateFormat, as "today" is different in different time zones).
Update the date format to include year, month and day:
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss z");
And then prepend the date string with the date you want:
simpleDateFormat.parse(today + " " + "12:32:21 JST");

A better solution using flexible default values (today instead of 1970-01-01) would be in Java-8 with the new built-in date-time-library located in package java.time:
String input = "12:32:21 JST";
String pattern = "HH:mm:ss z";
LocalDate today = LocalDate.now(ZoneId.of("Asia/Tokyo"));
DateTimeFormatter dtf =
new DateTimeFormatterBuilder().parseDefaulting(ChronoField.YEAR, today.getYear())
.parseDefaulting(ChronoField.MONTH_OF_YEAR, today.getMonthValue()).parseDefaulting(
ChronoField.DAY_OF_MONTH,
today.getDayOfMonth()
).appendPattern(pattern).toFormatter(Locale.ENGLISH);
ZonedDateTime zdt = ZonedDateTime.parse(input, dtf);
System.out.println(zdt); // 2016-12-23T12:32:21+09:00[Asia/Tokyo]
However, I still see a small bug related to the fact that this code makes a hardwired assumption about the used zone BEFORE parsing the real zone so please handle with care. Keep in mind that the current date depends on the zone. But maybe you only need to handle a scenario where just the Japan time is used by users.
Hint: You can also parse in two steps. First step with any kind of fixed default date in order to get the zone information of the text to be parsed. And then you can use this zone information for suggested solution above. An awkward but safe procedure.

You can use this code if you want to change only the year and the day
final SimpleDateFormat simpleDateFormatHour = new SimpleDateFormat("HH:mm:ss z");
Date date = simpleDateFormatHour.parse("12:32:21 JST");
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.YEAR, Calendar.getInstance().get(Calendar.YEAR));
calendar.set(Calendar.DAY_OF_YEAR, Calendar.getInstance().get(Calendar.DAY_OF_YEAR));
date = calendar.getTime();

Date in to UTC format Java

I have a string like this 2013-10-22T01:37:56. I Need to change this string into UTC Date format like this MM/dd/yyyy KK:mm:ss a. I have tried some code but it is not returning the UTC datetime.
My code is
String[] time = itsAlarmDttm.split("T");
String aFormatDate = time[0]+ " "+time[1];
String aRevisedDate = null;
try {
final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
final Date dateObj = sdf.parse(aFormatDate);
aRevisedDate = new SimpleDateFormat("MM/dd/yyyy KK:mm:ss a").format(dateObj);
System.out.println(aRevisedDate);
} catch (ParseException e) {
itsLogger.error("Error occured in Parsing the Data Time Object: " +e.getMessage());
} catch (Exception e) {
itsLogger.error("Error occured in Data Time Objecct: " +e.getMessage());
}
I am getting the output is MM/dd/yyyy KK:mm:ss a format. But Not UTC time format.
How to solve this issue?

Try this... Worked for me and printed 10/22/2013 01:37:56 AM Ofcourse this is your code only with little modifications.
final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
sdf.setTimeZone(TimeZone.getTimeZone("UTC")); // This line converts the given date into UTC time zone
final java.util.Date dateObj = sdf.parse("2013-10-22T01:37:56");
aRevisedDate = new SimpleDateFormat("MM/dd/yyyy KK:mm:ss a").format(dateObj);
System.out.println(aRevisedDate);

Try to format your date with the Z or z timezone flags:
new SimpleDateFormat("MM/dd/yyyy KK:mm:ss a Z").format(dateObj);

SimpleDateFormat sdf = new SimpleDateFormat( "yyyy-MM-dd HH:mm:ss" );
// or SimpleDateFormat sdf = new SimpleDateFormat( "MM/dd/yyyy KK:mm:ss a Z" );
sdf.setTimeZone( TimeZone.getTimeZone( "UTC" ) );
System.out.println( sdf.format( new Date() ) );

What Time Zones?
No where in your question do you mention time zone. What time zone is implied that input string? What time zone do you want for your output? And, UTC is a time zone (or lack thereof depending on your mindset) not a string format.
ISO 8601
Your input string is in ISO 8601 format, except that it lacks an offset from UTC.
Joda-Time
Here is some example code in Joda-Time 2.3 to show you how to handle time zones. Joda-Time has built-in default formatters for parsing and generating String representations of date-time values.
String input = "2013-10-22T01:37:56";
DateTime dateTimeUtc = new DateTime( input, DateTimeZone.UTC );
DateTime dateTimeMontréal = dateTimeUtc.withZone( DateTimeZone.forID( "America/Montreal" );
String output = dateTimeMontréal.toString();
As for generating string representations in other formats, search StackOverflow for "Joda format".

java.time
It’s about time someone provides the modern answer. The modern solution uses java.time, the modern Java date and time API. The classes SimpleDateFormat and Date used in the question and in a couple of the other answers are poorly designed and long outdated, the former in particular notoriously troublesome. TimeZone is poorly designed to. I recommend you avoid those.
ZoneId utc = ZoneId.of("Etc/UTC");
DateTimeFormatter targetFormatter = DateTimeFormatter.ofPattern(
"MM/dd/yyyy hh:mm:ss a zzz", Locale.ENGLISH);
String itsAlarmDttm = "2013-10-22T01:37:56";
ZonedDateTime utcDateTime = LocalDateTime.parse(itsAlarmDttm)
.atZone(ZoneId.systemDefault())
.withZoneSameInstant(utc);
String formatterUtcDateTime = utcDateTime.format(targetFormatter);
System.out.println(formatterUtcDateTime);
When running in my time zone, Europe/Copenhagen, the output is:
10/21/2013 11:37:56 PM UTC
I have assumed that the string you got was in the default time zone of your JVM, a fragile assumption since that default setting can be changed at any time from another part of your program or another programming running in the same JVM. If you can, instead specify time zone explicitly, for example ZoneId.of("Europe/Podgorica") or ZoneId.of("Asia/Kolkata").
I am exploiting the fact that you string is in ISO 8601 format, the format the the modern classes parse as their default, that is, without any explicit formatter.
I am using a ZonedDateTime for the result date-time because it allows us to format it with UTC in the formatted string to eliminate any and all doubt. For other purposes one would typically have wanted an OffsetDateTime or an Instant instead.
Links
Oracle tutorial: Date Time explaining how to use java.time.
Wikipedia article: ISO 8601

Converting datastamps to epoch (including GMT or UTC)

I am looking to convert timestamps into epoch (number of millisconds since 1970) - java.
I want an extensive parser - that supports both GMT/UTC and perheps other format.
For example:
new DateStamp("yyyy-MM-DD HH:mm:ss,ccc o").parse("2012-09-01 13:44:21222 GMT+2")
That is, I don't want to put in the actual format my self (GMT/UTC), but rather leave that for the parser.

You could use SimpleDateFormat:
DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss,S Z");
Date date = df.parse("2012-09-01 13:44:21,222 GMT+2:00");
long time = date.getTime(); // milliseconds since epoch
For ISO 8601 Time zone:
DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss,S Z");
Date date = df.parse("2012-09-01 13:44:21,222 +02");