Date! Time!

Oh, this is a big topic – and a long-time fascination of J, all the problems related to date and time. Including representation, time zones, standard/winter/summer/daylight-savings, et c.

(With lots of materials collect and maintained outside this CMS.)


  • Favvo! resources online:
  • Real-time, real time
      1. (noun) “Computersthe actual time elapsed in the performance of a computation by a computer,”
      2. (noun) “the result of the computation being required for the continuation of a physical process.
        the actual time during which a process takes place or an event occurs.”
      3. ‘idioms for real time’:
        “in real time, Informal. at once; instantaneously.”
      4. ‘adjective Computers’:
        “of or relating to applications in which the computer must respond as rapidly as required by the user or necessitated by the process being controlled.”
        “denoting or relating to a data-processing system in which a computer receives constantly changing data, such as information relating to air-traffic control, travel booking systems, etc, and processes it sufficiently rapidly to be able to control the source of the data”
    •, with for instance (other articles exist!):
      1. Hard – missing a deadline is a total system failure.
      2. Firm – infrequent deadline misses are tolerable, but may degrade the system’s quality of service. The usefulness of a result is zero after its deadline.
      3. Soft – the usefulness of a result degrades after its deadline, thereby degrading the system’s quality of service.

Live vs. real-time

Case Max Latency
Audio-visual 6 to 20 ms
Audio-only < 300 ms

Real-time signal processing is necessary, but not sufficient in and of itself, for live signal processing such as what is required in live event support. Live audio digital signal processing requires both real-time operation and a sufficient limit to throughput delay so as to be tolerable to performers using stage monitors or in-ear monitors and not noticeable as lip sync error by the audience also directly watching the performers. Tolerable limits to latency for live, real-time processing is a subject of investigation and debate but is estimated to be between 6 and 20 milliseconds.[9]

Real-time bidirectional telecommunications delays of less than 300 ms (“round trip” or twice the unidirectional delay) are considered “acceptable” to avoid undesired “talk-over” in conversation.


Near real-time
The term “near real-time” or “nearly real-time” (NRT), in telecommunications and computing, refers to the time delay introduced, by automated data processing or network transmission, between the occurrence of an event and the use of the processed data, such as for display or feedback and control purposes. For example, a near-real-time display depicts an event or situation as it existed at the current time minus the processing time, as nearly the time of the live event.[11]

The distinction between the terms “near real time” and “real time” is somewhat nebulous and must be defined for the situation at hand. The term implies that there are no significant delays.[11] In many cases, processing described as “real-time” would be more accurately described as “near real-time”.

Near real-time also refers to delayed real-time transmission of voice and video. It allows playing video images, in approximately real-time, without having to wait for an entire large video file to download. Incompatible databases can export/import to common flat files that the other database can import/export on a scheduled basis so that they can sync/share common data in “near real-time” with each other.

The distinction between “near real-time” and “real-time” varies, and the delay is dependent on the type and speed of the transmission. The delay in near real-time is typically of the order of several seconds to several minutes.[citation needed] Data processing modes or computing modes are classifications of different types of computer processing.

Real Time vs Batch Processing vs Stream Processing – (May 13, 2020)


The Difference Between Real-Time, Near Real-Time, and Batch Processing in Big Data –
(Jan 24, 2020)


Antonym to real time

On some form of spectrum:

‘Chance’, statistical Real-time Live
May or may not have happened or will happen Real-time with also limit on throughput, max latency.