LL first meta-model – ISA\LL\Elementary\Temporal

Parent

Elementary

Data
Temporal
Aliases None.
Information This assembly is about the elementary temporal elements.

To avoid common date and time treatment difficulties, date and time are always expressed as UTC time.
Note
Note kind Explanation
Text The Date and Time are parent of the Date time element. Both are Single and therefore the Value instance field is shared thru inheritance in the Date time type.

To do that, left most bits of the Value sbyte are reserved for the date and the right most for the time.

It is stated that the Date range must be at least ± 20 000 years. To do that 23 bits are required plus 1 sign bit: Giving 24 bits for the date.

It remains 40 bits for the time part in a Date time. Notice that for Date time the time part range is just 0:00 to 24:00. So there is no need for sign bit. With these 40 bits a time resolution of 0.1µs can be reached on a 1 day basis. This is stated as pretty good.

For Time outside of a Date time, the full 64 bits are available, but one is needed for the sign. This allows to support duration of several thousand of years.
Assembly data
Edition
Version 1
Country None.
Language  None.
Tirage 1
Dependencies None.
Inhibit all invariants False.
Scope Ideas.
Diagram
Classes
Date
Information The UTC date conventionally identified using the Gregorian calendar. This class accept negative dates.
Constructors
Date () Constructor initialized with the current UTC date.
Date (◈) Base constructor for building a Date.
Attributes
String The date as a string expressed according to ISO 8601 simplest format for date.
Example: 2018-03-26.The string follows this regular expression: -?\d{4}-((0[1-9])|(1[0-2]))-((0[1-9])|(1[0-9])|(2[0-9])|(3[0-1]))
$ : Temporal element Allows to get the value and to set the date value from an Temporal element with a date.
Invariant
The year 0 doesn’t exist
The starting year of the Gregorian calendar Christian era is year 1. The most recent year before the Christian era is -1.
The date range is ± 8 388 608 days
With a date resolution of 1 day the Date has an approximate range of ± 22 967 years.
Date
Date time
Information The UTC (ISO 8601) date time.

Here the Time is limited to only using 40 bits with a resolution of 0.1µs in order to store a full date in a Single. This makes the Date time perfectly suitable for time-stamping.
Constructors
Date  time() Constructor initialized with the current UTC date and time.
Date time (◈) Base constructor for building a Date time.
Date time (Date: Date, Time: Time)
 Constructor initialized with the provided UTC date and time.
Attributes
String The date and time as a string expressed according to ISO 8601 combined date and time representation.
Example: 2018-03-07T17:12:26,1234567.The string follows this regular expression: -?\d{4}-((0[1-9])|(1[0-2]))-((0[1-9])|(1[0-9])|(2[0-9])|(3[0-1]))T((([0-1])([0-9]))|(2[0-4])):([0-5])([0-9]):([0-5])([0-9]),\d{7}
$ : Temporal element Allows to get the value and to set the date time value from an Temporal element with a date and/or a time.
Date The UTC Date part of the Date time.
Time The UTC Time part of the Date time.
Query
⊥
 Indicates if the operand can be compared to this Date time. Typically a Date can be while a Time cannot.
Invariant
The time cannot be negative
In a day the time is always positive.
The time cannot exceed 24h
The maximum extends for the time of a day is 24 hours.
Date time
Temporal element
Information The root of almost all elementary date and time related types.
Temporal element
Time
Information A duration elapsed, forward or backward, since a reference point in time.The Sbyte have one sign bit. The remaining 63 bits encode the time quantity.

The time resolution is fixed to 0.1 microsecond.
Constructors
Time () Constructor initialized with the current UTC time.
Time (◈) Base constructor for building a Time.
Attributes
String The time as a string expressed according to ISO 8601 extended format for time with hour overriding.
Examples: 12:34:56,1234567 or -98765:43:21,1234567.The string follows this regular expression: -?\d{1,7}:([0-5])([0-9]):([0-5])([0-9]),\d{7}
$ : Temporal element Allows to get the value and to set the date value from an Temporal element with a time.
Invariant
The time range is ± 922 337 203 685 seconds
With a time resolution of 100 nanosecond the Time has an approximate range of ±292 years.
Time
Time offset
Information The UTC offset defined as the difference in hours and minutes from Coordinated Universal Time (UTC). It typically applies to a particular place and date.
Constructors
Time offset() Constructor initialized with the current UTC time offset.
Time offset (▣) The base constructor.
Property
Name The offset name has the UTC convention format for time offset ±hh:mm. Example: +01:00.

The string follows this regular expression: (±00:00)|((\+|-)((([0-1])([0-9]))|(2[0-4])):([0-5])([0-9]))
Invariant
Immutable
After initialization, a Time offset cannot be changed, in particular the setting thru attributes is not allowed.
The offset range is ± 24 hours
The offset cannot be wider than a day
Time offset
Zone date time
Information The date time for a particular geographic including an offset according to UTC standard (ISO 8601).
Constructors
Zone date time () Constructor initialized with the current Operating system UTC date, time and offset.
Zone date time (◈)
 The base constructor.
Zone date time (String: String, Zone name: String [0..1])
 Build a specific Zone date time from a full format UTC string :
YYYY-MM-DDThh:mm:ss.sTZD
Example: 1997-07-16T19:20:30.45+01:00
Attribute
String The zone time full UTC format string : YYYY-MM-DDThh:mm:ss.sTZD

Examples:

1994-11-05T08:15:30-05:00 corresponds to November 5, 1994, 8:15:30 am, US Eastern Standard Time.

1994-11-05T13:15:30Z corresponds to the same instant.
Date The UTC Date part of the Date time.
Time The UTC Time part of the Date time.
Offset The Time offset part of the Zone date time.
Zone name The zone given name.

Examples:

  • Australia;
  • I†;
  • Berlin, Lagos, Madrid, Paris, Rome, Tunis, Vienna, Warsaw .
Queries
=,⊥ Overrides the Type queries.
<, >, ≤, ≥ Overrides the Ordered queries.
Zone date time
Temporal element
Information The root of almost all elementary date and time related types.
Temporal element
Assemblies

None.

Version and status

Version Date Description Status
V1R1 31-Dec-17 Initial. Candidate

Related posts:

  1. Elements Assembly
  2. Textuals Assembly
  3. Metamodel Assembly
  4. Run time Assembly
  5. Errors Assembly

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