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Timestamps
A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolute notion of time, however. They can have any epoch, can be relative to any arbitrary time, such as the power-on time of a system, or to some arbitrary time in the past. A distinction is sometimes made between the terms datestamp, timestamp and date-timestamp: * Datestamp or DS: A date, for example -- according to ISO 8601 * Timestamp or TS: A time of day, for example :: using 24-hour clock * Date-timestamp or DTS: Date and time, for example --, :: History The term "timestamp" derives from rubber stamps used in offices to stamp the current date, and sometimes time, in ink on paper documents, to record when the document was received. Common examples of this type of timestamp are a postmark on a letter or the "in" and "out" times on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix Time
Unix time is a date and time representation widely used in computing. It measures time by the number of non-leap seconds that have elapsed since 00:00:00 Coordinated Universal Time, UTC on 1 January 1970, the Unix Epoch (computing), epoch. For example, at midnight on 1 January 2010, Unix time was 1262304000. Unix time originated as the system time of Unix operating systems. It has come to be widely used in other computer operating systems, file systems, programming languages, and databases. In modern computing, values are sometimes stored with higher Data granularity, granularity, such as microseconds or nanoseconds. Definition Unix time is currently defined as the number of non-leap seconds which have passed since 00:00:00UTC on Thursday, 1 January 1970, which is referred to as the ''Unix epoch (computing), epoch''. Unix time is typically encoded as a signed integer. The Unix time is exactly midnight UTC on 1 January 1970, with Unix time incrementing by 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trusted Timestamping
Trusted timestamping is the process of computer security, securely keeping track of the creation and modification time of a document. Security here means that no one—not even the owner of the document—should be able to change it once it has been recorded provided that the timestamper's integrity is never compromised. The administrative aspect involves setting up a publicly available, trusted timestamp management infrastructure to collect, process and renew timestamps. History The idea of timestamping information is centuries old. For example, when Robert Hooke discovered Hooke's law in 1660, he did not want to publish it yet, but wanted to be able to claim priority. So he published the anagram ''ceiiinosssttuv'' and later published the translation ''ut tensio sic vis'' (Latin for "as is the extension, so is the force"). Similarly, Galileo Galilei, Galileo first published his discovery of the phases of Venus in the anagram form. Sir Isaac Newton, in responding to questions f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decentralized Trusted Timestamping On The Blockchain
Trusted timestamping is the process of securely keeping track of the creation and modification time of a document. Security here means that no one—not even the owner of the document—should be able to change it once it has been recorded provided that the timestamper's integrity is never compromised. The administrative aspect involves setting up a publicly available, trusted timestamp management infrastructure to collect, process and renew timestamps. History The idea of timestamping information is centuries old. For example, when Robert Hooke discovered Hooke's law in 1660, he did not want to publish it yet, but wanted to be able to claim priority. So he published the anagram ''ceiiinosssttuv'' and later published the translation ''ut tensio sic vis'' (Latin for "as is the extension, so is the force"). Similarly, Galileo first published his discovery of the phases of Venus in the anagram form. Sir Isaac Newton, in responding to questions from Leibniz in a letter in 1677, co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timestamp-based Concurrency Control
In computer science, a timestamp-based concurrency control algorithm is a optimistic concurrency control method. It is used in some databases to safely handle transactions using timestamps. Operation Assumptions * Every timestamp value is unique and accurately represents an instant in time. * A higher-valued timestamp occurs later in time than a lower-valued timestamp. Generating a timestamp A number of different approaches can generate timestamps * Using the value of the system's clock at the start of a transaction as the timestamp. * Using a thread-safe shared counter that is incremented at the start of a transaction as the timestamp. * A combination of the above two methods. Formal definition Each transaction (T_i) is an ordered list of actions (A_). Before the transaction performs its first action (A_), it is marked with the current timestamp, or any other strictly totally ordered sequence: TS(T_i) = NOW(). Every transaction is also given an initially empty set of transacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stat (system Call)
is a Unix system call that queries the file system for metadata about a file (including special files such as directories). The metadata contains many fields including type, size, ownership, permissions and timestamps. For example, the command uses this system call to retrieve timestamps: * mtime: when last modified () * atime: when last accessed () * ctime: when last status changed () appeared in Version 1 Unix. It is among the few original Unix system calls to change, with Version 4's addition of group permissions and larger file size. Since at least 2004, the same-named shell command stat has been available for Linux to expose features of the system call via a command-line interface. Functions The C POSIX library header , found on POSIX and other Unix-like operating systems, declares stat() and related functions. int stat(const char *path, struct stat *buf); int lstat(const char *path, struct stat *buf); int fstat(int filedesc, struct stat *buf); Each ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO 8601
ISO 8601 is an international standard covering the worldwide exchange and communication of date and time-related data. It is maintained by the International Organization for Standardization (ISO) and was first published in 1988, with updates in 1991, 2000, 2004, and 2019, and an amendment in 2022. The standard provides a well-defined, unambiguous method of representing calendar dates and times in worldwide communications, especially to avoid misinterpreting numeric dates and times when such data is transferred between countries with different conventions for writing numeric dates and times. ISO 8601 applies to these representations and formats: ''dates'', in the Gregorian calendar (including the proleptic Gregorian calendar); ''times'', based on the 24-hour timekeeping system, with optional UTC offset; '' time intervals''; and combinations thereof.ISO 8601:2004 section 1 Scope The standard does not assign specific meaning to any element of the dates/times represented: t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File Archiver
In computing, a file archiver is utility software that combines computer file, files into a single archive file or in less common cases, multiple files. A minimally designed archiver might concatenate the content of files along with file file name, name and length. A more advanced archiver stores additional metadata, such as the Timestamping (computing), timestamps, file attributes and access control information. An archiver might lossless data compression, compress input file content to reduce the size of the resulting archive. The process of making an archive file is called ''archiving'' or ''packing''. Reconstructing the original files from an archive is called ''unarchiving'', ''unpacking'' or ''extracting''. Multics In the early days of computing, Multics provided the command a basic archiver without compression that descended from the Compatible Time-Sharing System, CTSS command of the same name. Multics also provided a magnetic tape archiver command, , which was perha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Zone
A time zone is an area which observes a uniform standard time for legal, Commerce, commercial and social purposes. Time zones tend to follow the boundaries between Country, countries and their Administrative division, subdivisions instead of strictly following longitude, because it is convenient for areas in frequent communication to keep the same time. Each time zone is defined by a standard offset from Coordinated Universal Time (UTC). The offsets range from UTC−12:00 to UTC+14:00, and are usually a whole number of hours, but a few zones are offset by an additional 30 or 45 minutes, such as in Indian Standard Time, India and Nepal Time, Nepal. Some areas in a time zone may use a different offset for part of the year, typically one hour ahead during spring (season), spring and summer, a practice known as daylight saving time (DST). List of UTC offsets In the table below, the locations that use daylight saving time (DST) are listed in their UTC offset when DST is ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
24-hour Clock
The modern 24-hour clock is the convention of timekeeping in which the day runs from midnight to midnight and is divided into 24 hours. This is indicated by the hours (and minutes) passed since midnight, from to , with as an option to indicate the end of the day. This system, as opposed to the 12-hour clock, is the most commonly used time notation in the world today, and is used by the international standard ISO 8601. A number of countries, particularly English speaking, use the 12-hour clock, or a mixture of the 24- and 12-hour time systems. In countries where the 12-hour clock is dominant, some professions prefer to use the 24-hour clock. For example, in the practice of medicine, the 24-hour clock is generally used in documentation of care as it prevents any ambiguity as to when events occurred in a patient's medical history. Description A time of day is written in the 24-hour notation in the form hh:mm (for example 01:23) or hh:mm:ss (for example, 01:23:45), where h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postmark
A postmark is a postal marking made on an envelope, parcel, postcard or the like, indicating the place, date and time that the item was delivered into the care of a postal service, or sometimes indicating where and when received or in transit. Modern postmarks are often applied simultaneously with the Cancellation (mail), cancellation or Killer (philately), killer that marks postage stamps as having been used. Sometimes a postmark alone is used to cancel stamps, and the two terms are often used interchangeably. Postmarks may be applied by handstamp or machine, using methods such as rollers or Inkjet printer, inkjets, while digital postmarks are a recent innovation. History The first postmark, called the "Bishop mark", was introduced by English Postmaster General of the United Kingdom, Postmaster General Henry Bishop (postmaster general), Henry Bishop in 1661 and showed only the day and month of mailing to prevent the delay of the mail by carriers. In England during the lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bates Numbering
Bates numbering (also known as Bates stamping, Bates branding, Bates coding or Bates labeling) is a method of sequentially Pagination, numbering pages with a reference number. A hand-operated Bates numbering device is used to "stamp" a number on a page, and the numbers will automatically advance after each stamping. Bates numbering is used in the legal, medical, and business fields to place one or more of identifying numbers, date and time marks on images and documents as they are scanned or processed, for example, during the Discovery (law), discovery stage of preparations for trial or identifying business receipts. Bates stamping can be used to mark and identify images with copyrights by putting a company name, logo, and/or legal copyright on them. This process provides identification, protection, and automatic consecutive numbering of the pages. History The Bates Automatic Numbering-Machine or Bates stamper is named after the inventor Edwin G. Bates, Edwin Granville Bates of Ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linked Timestamping
Linked timestamping is a type of trusted timestamping where issued time-stamps are related to each other. Each time-stamp would contain data that authenticates the time-stamp before it, the authentication would be authenticating the entire message, including the previous time-stamps authentication, making a chain. This makes it impossible to add a time-stamp in to the middle of the chain, as any time-stamps afterwards would be different. Description Linked timestamping creates time-stamp tokens which are dependent on each other, entangled in some authenticated data structure. Later modification of the issued time-stamps would invalidate this structure. The temporal order of issued time-stamps is also protected by this data structure, making backdating of the issued time-stamps impossible, even by the issuing server itself. The top of the authenticated data structure is generally ''published'' in some hard-to-modify and widely witnessed media, like printed newspaper or public bloc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
