The Calendar class is an abstract class that provides methods for converting between a specific instant in time and a set of calendar fields such as YEAR , MONTH , DAY_OF_MONTH , HOUR , and so on, and for manipulating the calendar fields, such as getting the date of the next week.

Java Calendar Class. Java Calendar class is an abstract class that provides methods for converting date between a specific instant in time and a set of calendar fields such as MONTH, YEAR, HOUR, etc. It inherits Object class and implements the Comparable interface.

The java calendar class is abstract and can’t be instantiated using the New operator, however there’s a method called getInstance() which returns a calendar object.

How to Create a Calendar in Java (4 Steps)

1. Type “import java. util.
2. Type “Calendar cal = Calendar. getInstance();” into your program wherever you need a calendar object in order to create a new calendar named cal with the current date and time.
3. Use the calendar object’s set(int Field, int Value) method to set the time you want your calendar object to represent.

How To Convert A String With A Date To A Calendar

1. SimpleDateFormat sdf = new SimpleDateFormat(
2. Date date = sdf. parse(strDate);
3. Calendar cal = Calendar. getInstance();
4. cal. setTime(date);

Date() : Creates date object representing current date and time. Date(long milliseconds) : Creates a date object for the given milliseconds since January 1, 1970, 00:00:00 GMT. Note : The last 4 constructors of the Date class are Deprecated.

Date/Time Formats

Format	Description
MM/DD/YY	Two-digit month, separator, two-digit day, separator, last two digits of year (example: 12/15/99)
YYYY/MM/DD	Four-digit year, separator, two-digit month, separator, two-digit day (example: 1999/12/15)

But it is old approach.

1. import java.text.SimpleDateFormat;
2. import java.util.Date;
3. public class CurrentDateTimeExample2 {
4. public static void main(String[] args) {
5. SimpleDateFormat formatter = new SimpleDateFormat(“dd/MM/yyyy HH:mm:ss”);
6. Date date = new Date();
7. System.out.println(formatter.format(date));
8. }

The Date in Java is not only a data type, like int or float, but a class. A Date in Java also includes the time, the year, the name of the day of the week, and the time zone. One of its methods includes extracting the time from the Date object.

A calendar date is stored internally as an integer value equal to the number of days since December 31, 1899. Because DATE values are stored as integers, you can use them in arithmetic expressions. For example, you can subtract a DATE value from another DATE value.

Date and Time data types

Data type	Format	Accuracy
time	hh:mm:ss[.nnnnnnn]	100 nanoseconds
date	YYYY-MM-DD	1 day
smalldatetime	YYYY-MM-DD hh:mm:ss	1 minute
datetime	YYYY-MM-DD hh:mm:ss[.nnn]	0.00333 second

The TIMESTAMP data type consists of a date and time, with optional time zone. (Optional) Indicates the number of digits of precision in the fractions of seconds, as an integer value from 0 to 9. The default is 6.

From Wikipedia: A timestamp is a sequence of characters, denoting the date and/or time at which a certain event occurred. A timestamp is the time at which an event is recorded by a computer, not the time of the event itself.

Dates are definitely quantitative, discrete data.

Timestamps in MySQL are generally used to track changes to records, and are often updated every time the record is changed. If you want to store a specific value you should use a datetime field.

Examples of timestamps: Thurs 01-01-2009 6:00. 2005-10-30 T 10:45 UTC. 2007-11-09 T 11:20 UTC.

current time

Timestamps are important for keeping records of when information is being exchanged or created or deleted online. In many cases, these records are simply useful for us to know about. But in some cases, a timestamp is more valuable.

Automated Timestamp Parsing

Timestamp Format	Example
yyyy-MM-dd*HH:mm:ss	2017-07-04*13:23:55
yy-MM-dd HH:mm:ss,SSS ZZZZ	11-02-11 16:47:35,985 +0000
yy-MM-dd HH:mm:ss,SSS	10-06-26 02:31:29,573
yy-MM-dd HH:mm:ss	10-04-19 12:00:17

The format of a TIMESTAMP is YYYY-MM-DD HH:MM:SS which is fixed at 19 characters. The TIMESTAMP value has a range from ‘1970-01-01 00:00:01’ UTC to ‘2038-01-19 03:14:07’ UTC . When you insert a TIMESTAMP value into a table, MySQL converts it from your connection’s time zone to UTC for storing.

Timestamps are markers in the transcription to indicate when the adjacent text was spoken. For example: Timestamps are in the format [HH:MM:SS] where HH, MM, and SS are hours, minutes, and seconds from the the beginning of the audio or video file. …

Timestamp (or date and time as it is more popularly known), was a common feature in many analog cameras. But the switch to DSLRs and eventually to smartphone cameras meant that this little feature got lost in the process. Thankfully now, the EXIF data of image stores all the information about time.

Convert from human-readable date to epoch long epoch = new java.text.SimpleDateFormat(“MM/dd/yyyy HH:mm:ss”).parse(“01/01/1970 01:00:00″).getTime() / 1000; Timestamp in seconds, remove ‘/1000’ for milliseconds. date +%s -d”Jan 1, 1980 00:00:01” Replace ‘-d’ with ‘-ud’ to input in GMT/UTC time.

Loading when this answer was accepted… The T doesn’t really stand for anything. It is just the separator that the ISO 8601 combined date-time format requires. You can read it as an abbreviation for Time. The Z stands for the Zero timezone, as it is offset by 0 from the Coordinated Universal Time (UTC).

The ISO 8601 standard defines formats for representing date-time values as text. The T is just a marker for where the time part begins. The Z is an abbreviation of +00:00 , meaning UTC (an offset of zero hour-minutes-seconds). Pronounced “Zulu” per military and aviation tradition.

The literal “Z” is actually part of the ISO 8601 datetime standard for UTC times. When “Z” (Zulu) is tacked on the end of a time, it indicates that that time is UTC, so really the literal Z is part of the time.

The Z stands for ‘Zulu’ – your times are in UTC. From Wikipedia: The UTC time zone is sometimes denoted by the letter Z—a reference to the equivalent nautical time zone (GMT), which has been denoted by a Z since about 1950.

Java 8Object Oriented ProgrammingProgramming. The Z means “zero hour offset”, also known as “Zulu time” (UTC) in the ISO 8601 time representation.

Zulu Time Zone is often used in aviation and the military as another name for UTC +0. Zulu Time Zone is also commonly used at sea between longitudes 7.5° West and 7.5° East. The letter Z may be used as a suffix to denote a time being in the Zulu Time Zone, such as 08:00Z or 0800Z.

Time Zone in “Zulu” Military Time, Time Zone

Current:	UTC
Current Offset:	No UTC/GMT offset
Difference:	4 hours ahead of New York