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AAT ICAS 2032 ✧ comparison of ICAS features

document note: this document is part of the Integrated Chronological Applications System (ICAS). Alliance for the Advancement of Technology (AAT) provides ICAS standards documents subject to terms of use described in document AAT ICAS 9010. please refer to other key AAT ICAS standards documents accessible via the AAT ICAS web site at for important information about ICAS.


comparison of ICAS features

this document describes comparisons of ICAS features with those of traditional calendar and clock scales used throughout many world societies. this document is not a complete comparison of scale features and is subject to further specification. please reference additional AAT ICAS documents for additional comparisons (2090, 2200, and so forth).


general use of calendar and clock

it is commonly established that readers can adapt to reading dates and times in a variety of different formats. however customs in large part determine how users approach the use of particular time and date formats. traditional scales of calendar and clock are reviewed for matters of practicability in light of new developments in areas of transportation, telecommunications, electronics, and computers.

decimal time is already a preferred format for the representation of clock times in areas of astronomy, computer science, and international standards. usability evaluations suggest that the use of decimal time can also be highly practicable for conventional use. recent developments suggest a reconsideration of calendar and clock interfaces in terms of initiatives for user-centered design.

for those uses of traditional scale time and date information that are not specified for monthtable processing (such as the date field options in a spreadsheet application); users may accommodate (and sometimes puzzle over) the use of time formats that are to some extent either concise, clear, or logically sortable. different applications and different conventions contribute to a variety of format approaches that pose a number of usability issues in the contexts in which people use time and date information. many of these usability issues are considered to be beneficial to only a marginal or insignificant extent. even so there may yet aggregate a variety of system maintenance issues in support of considerations for the use of uniform methods for the representation of dates and times. in certain cases such as Y2K, practices for formatting dates were reviewed to avoid disruptions to major systems. it may be that performance imrovements accommodated by the application of ICAS principles can account for more than marginal benefits when information is structured for interchange-readiness. (please see AAT ICAS 2021 and -2022 for additional information about Interform as a preferred ICAS convention).

as an emerging state of the art, ICAS systems and formats are more practicably structured for a system of the modern uses of calendar and clock scales. as a matter of usable design, ICAS designates practical or natural schemes such as alphabetical order and scalar coherence that are hypothesized to need less additional reinforcement in comparison with the use of traditional scales. ICAS formats can be expressed more practicably because of the use of uniform schemes and because of coherence with the main unit. with appropriately determined ICAS scales and features, users may more practicably express designated dates and times more clearly and more concisely than via the use of pre-uniform or pre-metric scales.

a unit of 1 day is a main unit in every terrestrial culture. however the chronological infrastructure and cultural heritage that surround the use of traditional scales of calendar and clock raise concerns about the development and use of uniform or metric scales. issues of training or development should be considered with regard to best practices for metrication. please see AAT ICAS 2034 for more information about metrication strategies, and AAT ICAS 2030 for training strategies.


daygroup scheduling

a review of traditional daygroup scheduling reflects the predominant use of the 7-day Gregorian week daygroup throughout many world societies. the use of a 7-day Gregorian week daygroup was observed during years dated by Julian calendar, and when the Gregorian calendar took effect the day-of-week proceeded without any discontinuity during the transition to a new day-of-month. the week is generally used for purposes of civil timekeeping; however the scheduling or designation of particular weekdays is determined differently by different regions and different organizations. different organizations moreover operate in accordance with different daygroup and time schedules.

a comparison of the Gregorian week and the uniform block daygroups concerns the coordination of daygroups to other calendar units. in the Gregorian calendar, years and months are coordinated with the Gregorian week daygroup with the effect that each year begins on a different week day. correspondingly, each day of a year occurs on a different weekday than which it had occurred on the previous year. the Gregorian week daygroup is used with the Uniform Calendar with the same effect (because the day-of-year number is the same for both the Gregorian and Uniform calendars). the uniform block daygroup is however uniformly coordinated with both uniform months and with New Calendar years. both the Gregorian week and the uniform block daygroups are essentially 7-day daygroups; yet each is coordinated differently with calendar years and months.

the number of full and partial 7-day Gregorian weeks for a Gregorian month can range from 4 to 6, and varies depending on the first weekday for a month and the number of days in the month. the number of Gregorian seventh days in a year can range from 52 or 53 depending on which weekday the year begins and whether the year is a leap year. schedules that are sensitive to or dependent upon the 7-day Gregorian week can also be used with the uniform months of the Uniform Calendar; however the number of full and partial weeks for a uniform month vary depending on which weekday the month begins.

Uniform Calendar uniform daygroups do not vary across uniform months except for yearend. as uniform daygroups are coherent to uniform months, each day of a uniform month occurs on the same uniform daygroup day for any uniform month. consequently the use of uniform months and uniform daygroups does not call for additional reference to the daygroup days of a previous or next month in determining a particular daygroup day. it is also simpler to determine the day-of-year number for a particular Uniform Calendar date, and likewise simpler to determine the number of days from a particular Uniform Calendar date to another. the uniform block daygroup provides 4 seventh days each month plus 2 monthspace days (48 seventh days plus 24 monthspace days plus 5 yearend days [or 6 yearend days in a leap year]).

the letters 'I' and 'O' are not designated for uniform months (for the reason that these letters are very similar to the numbers 0 and 1). however names beginning with letters 'I' and 'O' might be designable for the days of yearend. the letter 'I' could be represented in the yearend intercalation of even years; while the letter 'O' could be represented in the yearend observance of odd years.

although the days of the week and the block daygroups are tabulated differently with regard to months and years, sometimes the days of the block and the days of the week occur concurrently. when the week and block daygroups are concurrent, those accustomed to the Gregorian calendar have an opportunity to consider the concurrent representation of weekdays in terms of blockday colors.

a schedule of block-week concurrences is listed below:

AAT operations and web programming for have not been scheduled as daygroup-sensitive (however AAT has recently began using blockday information in timestamps). consequently, the use of the Uniform Calendar by AAT has occurred in relation to the traditional 7-day week daygroup in conventional use throughout society. the feasibility of the use of uniform daygroups is however approached by AAT in terms of constituting metrication issues rather than technical issues. in addition, other uniform daygroups may accommodate support for a range of additional applications such as automated processes that are not dependent on 7-day scheduling.

Uniform Calendar units provide a more practicable means of relating calendar dates with regard to uniform daygroups and uniform months. developers and users should consider that uniform daygroup scheduling may be more practicable in terms of the implementation, use, and maintenance of calendaring methods and applications. users should moreover consider that the uniform daygroup scheduling can accommodate the designation of both 7-day daygroup scheduling and day-of-month holiday scheduling independent of any disruption of schedules or operations that are sensitive to 7-day daygroup scheduling. experienced users may also find that these features and conditions can accommodate improvements in ways that users can reckon the validity or value of date expressions, thus facilitating a reduction of certain types of errors.


determining clock times

IDC units provide greater flexibility for users to practically express units expressed in terms of a particular IDC unit value in terms of other particular IDC unit values. this can be useful for calculating time values relating to the use of clocks by groups or for comparing time value totals for projects.

the first IDC decitriad is expressed to three numerical places plus a decitriad indicator 't', and is coherent to the designation of Uniform Calendar dates. SMH expressions to the minute are subject to four numerical places, plus a colon character-delimiter. those implementations of the SMH dial represented in terms of two half-day clock units also designate an 'am' and 'pm' indicator. the 'am' and 'pm' designations are not specified for redundant use in normative expressions of clock times, and are required for the clear expression of clock times unless the particular morning or afternoon time is established. this view is however subject to the widely-held convention that the '12' index functions as the zero point for a transition to the next half-day clock unit. certain conventional designations of the 'am' and 'pm' clock units are however not coherent to the designations of calendar dates. certain conventions for designating the half-day SMH dial do not regard the '12' index as a zero for purposes of designating times of 'midnight' or 'noon' in terms of 'am' or 'pm', and explain a clock time of 12:00 as a continuation of the prior '11' indices. users of the half-day SMH dial should be alert to the use of 'am' and 'pm' clock designators with regard to conflicting conventional uses.

subminor IDC clock units are comprised of 2 numerical places, as are SMH subminor clock units. however the IDC tik and tok are decimally coherent to the first IDC decitriad, while the seconds of the fractionally-constrained SMH clock dial are not decimally coherent to minutes, hours, or days.

certain domains of use, such as project planning and multimedia development, involve tasks for determining various calculable quantities of time. developers and users should consider that the various tasks involved in representing and expressing clock times may be accommodated more practicably by the use of IDC methods and applications. uses of both the decimal and the 24-60-60 scales involve tasks related to expressing designated clock units in terms of other clock units. human or user calculation of non-integer time quantities is simpler in a decimal system than for a 24-60-60 fractional system. it is also simpler to convert among various decimal quantities in a decimal system than it is to convert 24-60-60 fractional quantities to decimal quantities. moreover, quantities that are decimalized in terms of a particular 24-60-60 clock unit are often cumbersome for expression in terms of a different 24-60-60 clock unit. even apart from tasks related to calculating quantities of time, as in the case of a software application that calculates a complex quantity of time for a user; the use of an IDC scale can enhance user performance for tasks concerning user comparisons of various quantities of time.


data and metadata

the use of date and time information as data or metadata is ubiquitous in the organization, use, and interchange of information. ICAS formatting methods can accommodate a wide variety of methods for practicable uses of date and time expressions as data or as metadata.

some review of particular uses of 'ICAS in use' indicates that the representation of calendar days in terms of a color can enhance user experience of a calendar system. thus 'ICAS in use' localizations of the blockSpectrum daygroup might also consider the unique representation of the monthend and yearend days in terms of designated colors.

in addition to the representation of calendar days in terms of a daygroup day name or a daygroup day color, 'ICAS in use' localizations of the blockSpectrum daygroup might also consider the unique representation of the monthend and yearend days in terms of a designated icon or graphic. a systematic representation of daygroup days can thus enhance the organization or reference of date information that is situated in large data sets.

day to day for a general user, a calendar year is widely familiar as a large data set. yet organizations and communities tracking larger amounts of date information also work with much larger data sets. such users might find some very good opportunities for the enhancement of workflows, and the enhancement of user experience.

top document updated:

system identifiersdatetime
Uniform CalendarUCUCN 12019 S19 Yellow
Inter-Dial ClockIDCzone(UT)t339 tt050
'ICAS in use' can accommodate calendar and clock formatting 'for all people, for all time'.
day of yearD-o-YAD common year day139
Gregorian calendarGG2019 May 19 Sunday
seconds, minutes, hoursSMHUT08:08:14
style legend


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