unix timestamp milliseconds

What is a timestamp of milliseconds from 1970 called?

The timestamp is the total number of seconds from January 1, 1970 (08:00:00 GMT) to the current time, which is also known as the Unix timestamp.

Timestamp, a complete, verifiable piece of data that indicates that a piece of data has existed prior to a specific time, usually a sequence of characters that uniquely identifies a moment in time. The use of digital signature technology to generate data, the signature object includes the original document information, signature parameters, signature time and other information. Widely used in intellectual property protection, contract signature, financial accounts, electronic quotation bidding, stock trading and other aspects.

Time stamp refers to the Greenwich Mean Time on January 01, 1970, 00:00:00 seconds (Beijing time on January 01, 1970, 08:00:00 seconds) from the total number of seconds to the present.

In layman’s terms, a timestamp is a complete piece of verifiable data that can indicate that a piece of data has existed at a specific point in time. It is presented primarily to provide users with an electronic proof of when certain data of the user was created. In practice, it can be used in a variety of applications, including e-commerce, financial activities, and, in particular, can be used to support public key infrastructure “non-repudiation” services.

The Timestamp Specification standard provides for the preservation of timestamps, the backup of timestamps, the retrieval of timestamps, the deletion and destruction of timestamps, and the viewing and verification of timestamps.

Timestamp preservation includes preservation on the TSA (Timestamping Authority) side and preservation on the user side. The preservation on the TSA side involves the management of the timestamp database and the information items that the timestamp

record should contain, which should generally include, at a minimum, the time of entry, the serial number, the complete code, etc. The user side of the timestamp is generally managed by the user. Timestamps are generally saved on the user side by the user.

r language how to convert unix timestamp back to time

System.currentTimeMillis(): return the current system’s milliseconds, because the number of milliseconds obtained, so in the processing of UNIX timestamps need to be converted to seconds

That is:

longepoch=System. currentTimeMillis()/1000;


1. Get the UNIX timestamp for the current system

System.out.println(“Get system milliseconds method 1: “+Long.toString(newDate().getTime( )));

System.out.println(“Get system milliseconds method 2: “+Long.toString(System.currentTimeMillis()));

Note: the above code to get the number of milliseconds of the system, in the actual operation of the milliseconds we are generally recorded say for the accuracy of the record, when dealing with UNIX timestamps need to process the data.

2, the UNIX timestamp will be converted to the system can handle the time

System.out.println(“”+newjava.text.SimpleDateFormat(“yyyyMM-ddHH:mm:ss”).format(newjava.util. Date(1215782027390L)));

Output: 200807-1121:13:47

Note: At this point, the data processed for the system milliseconds is not a UNIX timestamp

3. Speak time converted to a UNIX timestamp

longepoch= newjava.text.SimpleDateFormat(“dd/MM/yyyyHH:mm:ss”).parse(“09/22/200816:33:00”).getTime();


Note! There is a difference in the handling of different time zones, so you need to be clear about your own time zone first.


System.out.println(“Current timezone: “+timezone_info);

System.out .println(“Time zone info: “+TimeZone.getDefault());


Current time zone:Asia/Shanghai

Time zone info:sun.util.calendar.ZoneInfo[id=”Asia/ Shanghai”,offset=28800000,dstSavings=0,useDaylight=false,transitions=19,lastRule=null]

Ways to handle different time zones:

SimpleDateFormatsd= newSimpleDateFormat(“yyyy-MM-ddHH:mm:ss”);


StringstrDate=sd.format( newDate(1215782027390L));

System.out.println(“Current time in GMT+8: “+strDate);


Current time in GMT+8:2008-07-1121:13:47

What is a Unix timestamp?

The Unix timestamp (Unixepoch, Unixtime, POSIXtime or Unixtimestamp in English)

is the number of seconds that have elapsed since January 1, 1970 (midnight UTC/GMT), without regard to leap seconds.

The 0 of the UNIX timestamp is standardized according to ISO8601 as: 1970-01-01T00:00:00Z.

An hour is represented as a UNIX timestamp in the format: 3600 seconds; a day is represented as a UNIX timestamp of 86400 seconds; leap seconds are not counted.

In most UNIX systems UNIX timestamps are stored as 32 bits, which triggers the year 2038 problem or Y2038.

The relationship between time zones, timestamps, time zones, Greenwich Mean Time (GMT), and Coordinated Universal Time (UTC)

From the example given in the comic, the timestamp here, refers to the Unix timestamp (Unixtimestamp). It is also known as Unix time (Unixtime), POSIX time (POSIXtime), and is a time representation defined as the total number of seconds from 00:00:00 GMT on January 01, 1970 until the present. So, technically, the timestamp at any point in time is the same no matter where you are on the planet. This is useful for online and client-side distributed applications to track time information uniformly.

It is the local flat solar time at the Royal Greenwich Observatory on the outskirts of London, England, because the Prime Meridian is defined as the meridian that passes through there.

People originally determined time by directly observing the position of the sun in the local sky, for example by using a sundial, and the time measured in this way was called local true solar time (localapparentsolartime/localapparenttime). Later, in order to solve the problem that the Earth’s orbit is not circular and there is an angle between the ecliptic and the equator and the uneven passage of time caused by the measurement, to the imaginary celestial body “flat Sun” (meanSun) as the benchmark for measuring time, and no longer to the real Sun as the benchmark, so that the measured time is called localmeansolartime ´╝łThe time thus measured is called local mean solar time (localmeansolartime/localmeantime). The difference between localmeansolartime and localmeantime is called equationoftime.

Later, the local mean solar time at the site of the Greenwich Observatory was defined as the worldwide standard of time, and became known as Greenwich Mean Time, with “mean time” being “mean solar time (meansolartime)”. Meantime” means “Meansolartime”.

The Mean Sun or False Sun is an imaginary celestial body that departs from the equinoxes at the same time as the real sun every year, travels from west to east on the celestial equator at a speed equal to the average speed of the real sun on the ecliptic, and finally returns to the equinoxes at the same time as the real sun.

The Flat Sun was proposed by the American astronomer Newcomb, mainly to get an evenly applicable daily time.

The flat solar day is the time displayed on a clock by human adjustment of the mean solar time obtained by observing the sun’s Sunday motion relative to the stars.

The Prime Meridian (English: Primemeridian), the 0 degree meridian, also known as the Greenwich Meridian, the Greenwich Meridian, or the Prime Meridian, is a line of longitude (also known as a meridian) that passes through the Greenwich Observatory in England. The east and west sides of the prime meridian are designated as east and west longitude, and meet at 180 degrees.

Time zones are regions of the Earth that use the same definition of time. Previously, time was determined by observing the position of the sun (the hour angle), which made the time different for places with different longitudes (local time.) In 1863, the concept of time zones was first used. Time zones partially solved this problem by establishing a standard time for a region.


The countries of the world are located at different positions on the Earth, so sunrise and sunset times in different countries, especially those that span from east to west, are bound to There are some deviations in the times of sunrise and sunset in different countries, especially in countries that span east and west. These deviations are known as jet lag.

IST-IndiaStandardTime-UTC+5:30, India Standard Time

IST-IsraelStandardTime-UTC+2:00, Israel Standard Time

CST-CentralStandardTime( USA)UTC-6:00, United States Standard Time

CST-CentralStandardTime(Australia)UTC+9:30, Australian Standard Time

CST-ChinaStandardTimeUT+8:00, China Standard Time

CST- CubaStandardTimeUT-4:00 Cuban Standard Time

Coordinated Universal Time (English: Coordinated Universal Time or UTC) is the predominant world time standard, which is based on the length of the second in atomic time, and is as close as possible to Greenwich Mean Time (GMT) in terms of the time of day.

Coordinated Universal Time (UTC) is the world’s primary time standard for regulating clocks and time, which does not differ by more than one second from flat solar time at 0 degrees longitude[4] and does not observe Daylight Saving Time. Coordinated Universal Time (UTC) is one of several alternative time systems closest to Greenwich Mean Time (GMT). For most uses, UTC time is considered interchangeable with GMT time, but GMT time is no longer established by the scientific community.

UTC divides time into days, hours, minutes, and seconds. Typically, days are defined using the Gregorian (Gregorian) calendar, but the Julian day can also be used. Each day contains 24 hours and each hour contains 60 minutes. A minute usually has 60 seconds, but with the addition of random leap seconds, a minute may be 61 or 59 seconds [11]. Thus, in the time scale of the UTC system, seconds and units smaller than seconds (milliseconds, microseconds, etc.) have a fixed length, but for minutes and units larger than that (hours, days, weeks, etc.), the length is variable. The decision to insert a leap second is made by the International Earth Rotation Service (IERS) and is published in the organization’s “Bulletin C” at least six months before accession [12][13]. Leap seconds cannot be predicted far in advance because the Earth’s rotation rate is unpredictable [14].


International standard ISO 8601, is the International Organization for Standardization’s method of representing date and time, known as Forms of Data Storage and Exchange – Information Exchange – Representation of Date and Time.


The timestamp is the total number of seconds from 00:00:00 GMT on January 01, 1970 (08:00:00 GMT on January 01, 1970) to the present. In layman’s terms, a timestamp is a complete piece of verifiable data that can indicate that a piece of data has existed at a specific point in time. It is primarily proposed to provide users with an electronic proof of when certain data of the user was generated. In practice, it can be used in a variety of applications, including e-commerce, financial activities, and, in particular, to support the “non-repudiation” services of public key infrastructures (PKIs).

What is a timestamp?

Timestamp is the number of seconds since





day (00:00:00

gmt) in 1970

. It is also known as a




timestamp, or unix

time, or posix

time, is a time representation defined as the total number of seconds from 00:00:00 GMT on January 01, 1970 to the current total number of seconds. unix timestamps are widely used not only in unix systems, unix-like systems, but also in many other operating systems.