[java] java.util.Date format SSSSSS: if not microseconds what are the last 3 digits?

Just tested this code on both my Windows (8) workstation and an AIX:

    public static void main(String[] args) {
        System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS").format(new Date()));
        System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS").format(new Date()));

and got something similar to this as a result:

2013-10-07 12:53:26.000905
2013-10-07 12:53:26.000906

Can someone please explain me what are the last digits, if not microseconds?

Note: I interact with a DB2 database in which chronological data is stored using timed columns as TIMESTAMP with 6 digits AFTER the seconds i.e. microseconds (IMO). But all those "timestamps" are created by requesting the following query:

SELECT current timestamp as currenttimestamp FROM Table ( values (1)) temp

I wonder if, given the above results, I couldn't just use in my code new Date() instead of selecting the current timestamp from the database.


PS: I searched but found no relevant (answered) questions, like: Current time in microseconds in java or Get time with hour, minute, second, millisecond, microsecond

This question is related to java date format timestamp

The answer is






The accepted Answer by ppeterka is correct. Your abuse of the formatting pattern results in an erroneous display of data, while the internal value is always limited milliseconds.

The troublesome SimpleDateFormat and Date classes you are using are now legacy, supplanted by the java.time classes. The java.time classes handle nanoseconds resolution, much finer than the milliseconds limit of the legacy classes.

The equivalent to java.util.Date is java.time.Instant. You can even convert between them using new methods added to the old classes.

Instant instant = myJavaUtilDate.toInstant() ;

The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction).

Capture the current moment in UTC. Java 8 captures the current moment in milliseconds, while a new Clock implementation in Java 9 captures the moment in finer granularity, typically microseconds though it depends on the capabilities of your computer hardware clock & OS & JVM implementation.

Instant instant = Instant.now() ;

Generate a String in standard ISO 8601 format.

String output = instant.toString() ;


To generate strings in other formats, search Stack Overflow for DateTimeFormatter, already covered many times.

To adjust into a time zone other than UTC, use ZonedDateTime.

ZonedDateTime zdt = instant.atZone( ZoneId.of( "Pacific/Auckland" ) ) ;

About java.time

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.

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

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

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

Use java.sql.Timestamp.toString if you want to get fractional seconds in text representation. The difference betwen Timestamp from DB and Java Date is that DB precision is nanoseconds while Java Date precision is milliseconds.

SSSSSS is microseconds. Let us say the time is 10:30:22 (Seconds 22) and 10:30:22.1 would be 22 seconds and 1/10 of a second . Extending the same logic , 10:32.22.000132 would be 22 seconds and 132/1,000,000 of a second, which is nothing but microseconds.

I used yet another trick to format date with 6-digit precision (microseconds):

    new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.").format(microseconds/1000)
    +String.format("%06d", microseconds%1000000));

This technique can be extended further, to nanoseconds and up.

Examples related to java

Under what circumstances can I call findViewById with an Options Menu / Action Bar item? How much should a function trust another function How to implement a simple scenario the OO way Two constructors How do I get some variable from another class in Java? this in equals method How to split a string in two and store it in a field How to do perspective fixing? String index out of range: 4 My eclipse won't open, i download the bundle pack it keeps saying error log

Examples related to date

How do I format {{$timestamp}} as MM/DD/YYYY in Postman? iOS Swift - Get the Current Local Time and Date Timestamp Typescript Date Type? how to convert current date to YYYY-MM-DD format with angular 2 SQL Server date format yyyymmdd Date to milliseconds and back to date in Swift Check if date is a valid one change the date format in laravel view page Moment js get first and last day of current month How can I convert a date into an integer?

Examples related to format

Brackets.io: Is there a way to auto indent / format <html> Oracle SQL - DATE greater than statement What does this format means T00:00:00.000Z? How to format date in angularjs How do I change data-type of pandas data frame to string with a defined format? How to pad a string to a fixed length with spaces in Python? How to format current time using a yyyyMMddHHmmss format? java.util.Date format SSSSSS: if not microseconds what are the last 3 digits? Formatting a double to two decimal places How enable auto-format code for Intellij IDEA?

Examples related to timestamp

concat yesterdays date with a specific time How do I format {{$timestamp}} as MM/DD/YYYY in Postman? iOS Swift - Get the Current Local Time and Date Timestamp Pandas: Convert Timestamp to datetime.date Spark DataFrame TimestampType - how to get Year, Month, Day values from field? What exactly does the T and Z mean in timestamp? What does this format means T00:00:00.000Z? Swift - iOS - Dates and times in different format Convert timestamp to string Timestamp with a millisecond precision: How to save them in MySQL