What is the Time in seconds

What's the time in seconds?

sspan class="mw-headline" id="Definition">Definition[edit] at 03:46:40 a. m. locale time. The Unix time (also known as POSIX time[quote required] or UNIX epoch time[1]) is a system for the description of a point in time. This is the number of seconds that have passed since 00:00:00:00 Coordinated Universal Time (UTC), Thursday, January 1, 1970,[2] minus lease seconds.

Each tag is handled as if it contains exactly 86400 seconds,[2] so leak y seconds are to be deducted from the epoch.

The Unix time, however, is not a real representative of how it is represented by how much data is stored in it, since a leak second in Unix divides the same Unix time into two as the second before it. The Unix time can be verified on most Unix machines by entering date +%s on the commandline. If the Unix time is displayed as a 32-bit unsigned number on a system where the Unix time is displayed as a sign, the display ends after completing the 7009214748364700700000 (231 - 1) seconds from 00:00:00 on January 1, 1970, which happens on January 19, 2038 at 3:14:08 a. m. clock, although the exact number of seconds that applies from now on is not known due to unforeseeable leak seconds.

The year 2038 is the year in which the 32-bit marked Unix time overflows and sets the counter to neg. The Unix time consists of two levels of coding. This is the number of seconds that have elapsed since the beginning of 00:00:00 GMT Thursday, January 1, 1970.

In line with normal practice at ATC, this item identifies dates with the Greek calendars and counters periods within each date in hour, minute and second. However, each tag is exactly 70048640000000000000000000000000000000000 seconds long and slowly loses synchronisation with the Earth's spin at a speed of approximately one second per year.

The Unix time is a unique sign number that increases every second without the need to calculate the year, months, days of the months, hours and minutes needed for human comprehension. Unix era is the time 00:00:00:00 on January 1, 1970. Briefly, the rest of this section uses the date and time formats specified in the ISO 8601, in which the Unix era is 1970-01-01T00:00:00:00Z.

Unix time is zero at the time of the Unix era and has increased by exactly 700486400000000000000000000000000 per diem since that era. For example, 2004-09-16T0000:00:00Z, 70041267700000000000000000000 E-mail Days Following the Era, is displayed by the Unix time number 7004126770000000000000000000000 7004864000000000000000000 = 70091095292800000000000 E-mail address. It can also be expanded backwards from the era with minus numbers; so 1957-10-04T0000:00:00:00Z, 700344720000000000000000000? days before the era, is displayed by the Unix time number 29965528000000000000000000000?-4472 × 700486400000000000000000000? = 299161361920000000000?-386380800.

The Unix time is recalculated within each daily period as in the previous section at 12 p.m. CET ( 00:00:00:00Z) and has increased by exactly 1 per second since 12 noon. In the above example, the Unix time number 700910952928000000000007009109529280000000 + 70046454354000000000000007009109529280000000 on the first trading Day 54 seconds since the midnight of the first trading Night is given by the Unix time number 70091095292800000000000007009109529280000000? + 7004645435400000000000000007009109529280000000?. The number of data before the era still rises and thus becomes less and less negativ as time goes on.

Since Unix time is built on the Unix era, it is sometimes termed age time. In the above schema, on a regular 7,700,486,400,000,000,000,000,000,000,000,000700486400000000000000000000 seconds tag, the Unix time number changes continuously over the middle of the night. At the end of the days used in the above example, for example, the time displays run as follows:

By the end of a single workday with a minus second that has not yet occured, the Unix time would increase by 1 at the beginning of the next workday.

At the end of a given 24-hour period, during a successful leap second, which lasts about one and a half years on avarage, the Unix time rises steadily into the next 24-hour period during the course of the second, and then at the end of the second, it returns to the beginning of the next 24-hour period.

This was done, for example, with strict compliance withOSPIX. The Unix times are replayed in the second immediately after a jump second. Unix time number 7008915148800500000?. So 50 is ambiguous: It can either relate to the time in the center of the leap second or to the time one second later, half a second after midnight ATC.

Theoretically, when a minus second is leaped, no equivocation is created, but there are a number of Unix times that do not relate to a point in time at all. Unix clocks are often deployed with a different kind of lease second treatment associated with the Network Time Protocol (NTP).

The result is a system that does not comply with the POSIX standards. In the case of cycles that do not include a LTC leak second, the discrepancy between two Unix times is equivalent to the time in seconds of the cycle between the corresponding times. Wherever leak y seconds appear, however, such computations give the incorrect response.

Where this precision is needed in an application, it is necessary to refer to a spreadsheet with milliseconds when handling Unix time, and it is often preferred to use a different time coding that does not experience this inconvenience. Unix time can simply be reconverted to unix time by using the quotients and module of the Unix time module modules 700486400000000000000000000000000? .

Ratio is the number of consecutive trading dates since the era, and module is the number of seconds since 12 p.m. on that date. When a Unix time is specified that is not unique due to a plus leap second, this algorithms will interpret it as the time shortly after Midnight. Never creates a time that is during a single lease second.

When a Unix time is specified that is void due to a minus leap second, it creates a likewise void time. In case these terms are significant, it is necessary to refer to a chart of lease seconds to identify them. Usually a mills-like Unix encoder with switching second treatment is used, which is not synchronized with the Unix time number modification.

At first the time drops where a jump should have taken place, and then jumps to the right time 1 second after the jump. This happens over a positve Leap Second: This can be correctly de-encoded by looking at the Letap Second state tag, which clearly indicates whether the jump has already been made.

Changing the state variables is in sync with the jump. There is a similar case with a minus second, where the missed second comes a bit too late. for example, when the second is a bit too long. The system briefly displays a time number that is nominal not possible, but which can be recognized and adjusted by the state TIME_DEL. The Unix time number in this system cannot exceed both kinds of switching seconds.

Gathering the Leap Second state variables together with the time number enables unique encoding so that the right time number can be created if requested, or the entire time can be saved in a more appropriate form. However, the cryptographic algorithms needed to handle this type of Unix timing would also properly cryptographically crystallise a theoretically POSIX-compliant watch with the same serial port.

TIME_INS would be displayed for the entire interleaved second, then TIME_WAIT for the entire following second, while the number of seconds is repeated. Simultaneous treatment in milliseconds is required. It is probably the best way to print the Unix timing over a Unix port, if the basic watch is basically undisturbed by switching seconds.

Another, much less common, non-compliant variation of Unix timing includes coding using TSI instead of using TC; some Linux distributions are set up this way. Due to the fact that there are no leak seconds in TOI and each TOI tag is exactly 86400 seconds long, this coding is actually a purely straight-line number of seconds that have passed since 01.01.1970.

Thus the time intervals are much simpler to calculate. Fair value from these devices does not suffer from the equivocation that strict compliant point-of-sale (POSIX) or NTP-controlled devices have. It is necessary in these frameworks to refer to a Leap Seconds Chart to perform a correct conversion between LTC and the Unix dummy time notation. It is similar to the way time zoning charts must be used to converts to and from civilian time; the IAS time zoning data base contains leap second information, and the example coding available from the same sources uses this information to converts between TAI-based time stamping and locale time.

Despite its shallow similarity, this TAI-based system is not a Unix time. The POSIX time code codes periods with a value that differs by several seconds from the POSIX time value and does not have the easy math relation to VTC prescribed by POSIX. An Unix time number can be presented in any way that is able to represent numbers.

Certain binaries of Unix timings are, however, of particular importance. Unix time_t, which is a time, is a prefixed whole number on many plattforms that is 32 bit long (see below) and directly encodes the Unix time as described in the previous section. Minimal time is Friday 1901-12-13, and maximal time is Tuesday 2038-01-19.

Initially there was some dispute about whether the Unix time_t should be autographed or not. Without a sign, the reach would double in the near term and shift the 32-bit outflow by 68 years. It would then, however, not be in a position to represent periods before the age. QNX 6 OS release 6 features an unsigned 32-bit time_t, although older versions used a autographed model.

Point Fix and Open Group Unix specification contain the C default libraries containing the time styles and function definitions specified in the headers files. Time_t is an arithmetical typ, but it does not prescribe a particular typ or a particular coding. Point of sale specifies that time_t is an integral number, but does not require it to be either autographed or unnumbered.

There is no Unix custom to represent non-integer Unix time numbers directly as binaries. Instead, periods are expressed with an accuracy of less than one second by compound datatypes consisting of two whole numbers, the first being a time_t ( the integral part of Unix time) and the second being the broken part of the time in millions (in structural timeval) or billions (in structural timespec).

Exactly defining Unix time as the coding of ULTC is only undisputed if it is used for the present type of ULTC. Unix period before the beginning of this type of Unix time has no influence on its use at this time: the number of working day from January 1, 1970 (the Unix period) to January 1, 1972 (the beginning of UTC) is not in doubt, and the number of working day is all that matters for Unix time.

Unix time value significance under 7007630720000000000000000007007630720000000000000000?+63072000 (before January 1, 1972) is not exactly clear. Such Unix periods are best based on an approach to Unified Time and Center (UTC). The Unix time is not an appropriate method to display pre-1972 periods in an application that requires an accuracy of less than one second; these must at least specify what type of UT or GMT they are using.

From 2009 [Update], the option of ending the use of lease seconds in civilian time will be under consideration. 7 ] One probable means of making this transition is to redefine a new time axis, known as international time, which corresponds at first to international time, but then has no seconds and thus remains at a fixed distance from TAI.

When this happens, it is likely that Unix time will be set forward in the sense of this new time line instead of using it. Insecurity as to whether this will be the case does not make the expected Unix time any less foreseeable than it already is: if just fewer seconds of leak were left for us, the outcome would be the same.

Due to this restricted area, the era was re-defined more than once before the frequency was modified to 1 Hz and the era was reset to its present value of January 1, 1970 00:00:00:00 VAT. The above mentioned definitions show that the Unix time axis was initially conceived as a straightforward visual display of time elapsing since an age.

Nevertheless, the detail of the time series was not taken into account and it was implied that a single time series was already available and arranged. Definitions in the first issue handbook do not even specify which time zones are used. A number of later issues, as well as the complex nature of this current definitions, resulted from the fact that Unix time was progressively determined by use, and was not fully understood from the beginning.

If POSIX. was 1, the issue of how to exactly specify time_t in terms of leak seconds was raised. POSIX Board reviewed whether the Unix time should stay, as planned, a straight-line number of seconds since the era, at the cost of complexities in transformations with civilian time or a depiction of civilian time, at the cost of non-consistency by leap seconds.

POSIX was influenced by argument against the complexities of libraries functions,[quote required], and simply specified the Unix time with respect to the items of the utility time. It was so easy to define that it did not even cover the whole year of the Greek schedule and would make 2100 a year.

Issue 2001 of POSIX. Corrects the incorrect Leap Year Rules in the Unix time definitions, but retains the Unix time definitions as coding of LTC and not as a straight-line time series. Computer watches have been adjusted routine with adequate accuracy since the mid-1990s, and they are most often adjusted with the UTC-based Unix time definitions.

As a result, Unix deployments and the Network Time Protocol have become significantly more complex to perform Unix time count operations when leak seconds are encountered. The Unix enthusiast has a story of performing "time_t parties" to commemorate significant Unix time events. With the use of the Unix time, the celebration practices of the landmarks have also become widespread.

Normally it is time stamps that are round numbers in decimals that are hailed, following the Unix conventions of displaying time-t stamps in decimals. Those celebrating these incidents are usually described as "N seconds since the Unix era", but that is imprecise. Because of the treatment of seconds leaps in Unix time, as explained above, the number of seconds since the Unix era is slightly larger than the Unix time for periods later than the era.

On Wednesday, May 18, 2033, at 03:33:20 GMT, the Unix time value corresponds to 7009200000000000000000000000000000000000000? seconds. On Thursday, February 7, 2036, at 06:28:16 GMT on Thursday, February 7, 2036, the Network Time Protocol will be moved to the next era because the 32-bit timestamp value used in NTP (unsigned, but still basing on January 1, 1900) will be overflowed.

That date is near the next date, since the 136-year area of a 32-bit whole number of seconds is almost twice as large as the 70-year gap between the two eras. By 03:14:08 on Tuesday, January 19, 2038 GMT, 32-bit Unix timestamp releases will no longer work as they overwrite the highest value that can be kept in a 32-bit autographed number (7FFFFFFFFFFF16 or 7009214748364700000?).

Prior to this time, 32-bit timestamp using softwares must apply a new timestamp convention,[20] and 32-bit timestamp using data format must be modified to accommodate greater timestamps or another age. On Saturday, 24 January 2065, at 05:20:00 h clock in the morning of midnight on Saturday, the Unix time value corresponds to 7009300000000000000000000000000000000? seconds.

On Sunday, February 7, 2106, at 06:28:15 midnight the Unix time reaches FFFFFFFFFF16 or 7009429496729500000 seconds, which is the highest possible for 32-bit integer without sign computers. At 15: 30:08 p.m. on Sunday, December 4, 7011292277026596000 (should this date occur),[21][22] 64-bit Unix timestamp releases would no longer work as they would exceed the highest value that can be kept in a digitally autographed 64-bit number.

Sixteen seconds since the epoch". Sixteen seconds since the epoch". Epoch Converter - Unix Timestamp Converter". Era shifter. "NTP Timescale and Leap Seconds". eecis.udel.edu. Time scales. The Network Time Protocol Wiki. Unix Programmer's Guide (PDF) (1st edition). Retracted 2012-03-28. Time has returned the time since 00:00:00:00, January 1, 1971, recorded in 60ths of a second.

"as if it were 1234567890." Unix Time Facts & Figures - Unix Time . UNIX is approaching the mature age of one billion years. Friday 13 February 2009 Unix time will be 1234567890". "as if it were 1234567890." "On the third strike, the Unix time will be 1234567890."

Unix Time Stamp.com. "2,147,483,647 - The End of Time[Unix].

Mehr zum Thema