Commons Dates and Times Ontology
type: Ontology
abstract: The dates and times ontology defines commonly used temporal concepts that cover those most frequently needed across domains, with a focus on terminology that is used in business applications. It is designed to be mappable to other date and time ontologies and specifications, such as the W3C Time Ontology in OWL (available at https://www.w3.org/TR/owl-time/), certain temporal elements in BFO 2020 (see https://basic-formal-ontology.org/bfo-2020.html), time concepts defined in schema.org, and the Object Management Group's Date Time Vocabulary (DTV) specification (available at https://www.omg.org/spec/DTV/), without the corresponding overhead or in some cases, issues. The concepts were originally derived from a number of date and time standards including ISO 8601:2004 Representation of Dates and Times. The ontology itself was derived from the Financial Industry Business Ontology (FIBO) Financial Dates ontology, with minor revisions to better reflect requirements for mapping to other ontologies.
contributor: Elisa Kendall, Thematix Partners LLC
contributor: Mark Linehan, Thematix Partners LLC
contributor: Pete Rivett, Federated Knowledge LLC
license: Copyright (c) 2014-2025 EDM Council, Inc. Copyright (c) 2014-2025 Object Management Group, Inc. Copyright (c) 2014-2025 Thematix Partners LLC Copyright (c) 2021-2025 agnos.ai U.K. Ltd Copyright (c) 2023-2025 Federated Knowledge LLC Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. See https://opensource.org/licenses/MIT.
imports: AnnotationVocabulary
version IRI: DatesAndTimes
change note: https://www.omg.org/spec/Commons/20220501/DatesAndTimes.rdf version of this ontology was modified to eliminate a double space in the scope note on CombinedDateTime (COMMONS-6).
change note: https://www.omg.org/spec/Commons/20221101/DatesAndTimes.rdf version of this ontology was revised to add properties supporting start and end time and related concepts (COMMONS-11-8).
change note: https://www.omg.org/spec/Commons/20230801/DatesAndTimes.rdf version of this ontology was revised to correct an annotation on DateTime (COMMONS-13-20) and to revise the notes on DatePeriod to allow for cases where a date period, such as 5 days, is known but the start and end of that period are not known (COMMONS-13-19).
note: The dates and times ontology conforms with the OWL 2 DL semantics, and is outside of OWL 2 RL due to the inclusion of exact cardinality constraints on explicit date, explicit duration and time of day. These constraints can be changed to maximum cardinality constraints if needed to support OWL RL rule-based applications that cannot be extended to support them.
copyright: Copyright (c) 2014-2025 EDM Council, Inc.
copyright: Copyright (c) 2014-2025 Object Management Group, Inc.
copyright: Copyright (c) 2014-2025 Thematix Partners LLC
copyright: Copyright (c) 2021-2025 agnos.ai U.K. Ltd
copyright: Copyright (c) 2023-2025 Federated Knowledge LLC

combined date time
type: Datatype
equivalent class: Datatype
  union of: string
  union of: dateTime
  union of: dateTimeStamp
definition: datatype that maps to several base types for dates and times
note: Valid values must use the ISO 8601 representation for a date, or the corresponding XML Schema Datatypes representation for a date and time, or date and time including the time zone.
scope note: There are many cases where the representation of a date may or may not include a time, and where the underlying data representation varies. This composite datatype should only be used in cases where a standard representation using one of the options in the union for date or date and time value specification does not work.

date
type: Class
subclass of: time instant
subclass of: Restriction
  on property: has date value
  max qualified cardinality: 1
  on data range: string
definition: calendar day on some calendar
note: A date may or may not have a value, and may be explicit or calculated. A date that has a value is one that is either explicitly set as a literal when it is created, or is some form of 'calculated date'. In an instance of date, the existence of the 'has date value' property both indicates that the date is known, and gives the value of the date. A date that does not have a value is likely one that is some form of 'calculated date, in which the actual date has not (yet) been established.

date period
type: Class
subclass of: time interval
subclass of: Restriction
  on property: has end date
  on class: date
  max qualified cardinality: 1
subclass of: Restriction
  on property: has start date
  on class: date
  max qualified cardinality: 1
subclass of: Restriction
  on property: has duration
  on class: duration
  max qualified cardinality: 1
definition: time span over one or more calendar days
note: A date period is considered unknown or incomplete if either the start date or the end date has no value. There may be cases, however, when the length of time is known, such as a 4-day work week, but the precise start and end of that week are not known.
note: A date period is typically defined by at least two of three properties: (1) a start date, (2) an end date, and (3) a duration. If more than one of these properties is missing, the date period may be invalid, incomplete, or unknown.

date time
type: Class
subclass of: time instant
subclass of: Restriction
  on property: has date time value
  max qualified cardinality: 1
  on data range: dateTime
definition: time point including a date and a time, optionally including a time zone offset
note: 'has date time value' is omitted if the 'date time' is not (yet) known. The time zone is implicitly UTC.

date time stamp
type: Class
subclass of: time instant
subclass of: Restriction
  on property: has date time stamp value
  max qualified cardinality: 1
  on data range: dateTimeStamp
definition: time point including a date and a time that requires a time zone offset
note: 'has date time stamp value' is omitted if the 'date time stamp' is not (yet) established.
synonym: time stamp

day
type: NamedIndividual
type: explicit duration
definition: explicit period of 24 hours
has duration value: P1D

duration
type: Class
subclass of: time interval
subclass of: Restriction
  on property: has duration value
  max qualified cardinality: 1
  on data range: string
definition: interval of time of some specific length
note: The 'has duration value' property is absent if the duration is not (yet) known.

explicit date
type: Class
subclass of: date
subclass of: Restriction
  on property: has date value
  on data range: string
  qualified cardinality: 1
definition: date in which the 'has date value' property is required

explicit date period
type: Class
subclass of: date period
subclass of: proper interval
subclass of: Restriction
  on property: has end date
  on class: explicit date
  max qualified cardinality: 1
subclass of: Restriction
  on property: has start date
  on class: explicit date
  max qualified cardinality: 1
subclass of: Restriction
  on property: has duration
  on class: explicit duration
  max qualified cardinality: 1
definition: date period for which the start date, end date, and/or duration are required
note: As with 'date period', any one of {start date, end date, duration} may be omitted because the missing property can be inferred from the other two.

explicit duration
type: Class
subclass of: duration
subclass of: proper interval
subclass of: Restriction
  on property: has duration value
  on data range: string
  qualified cardinality: 1
definition: duration for which the 'has duration value' property must have a value
note: This class is used when a duration is guaranteed to be known when it is created.

explicit time period
type: Class
subclass of: proper interval
subclass of: time period
subclass of: Restriction
  on property: has duration
  on class: explicit duration
  max qualified cardinality: 1
subclass of: Restriction
  on property: has end time
  on class: time of day
  max qualified cardinality: 1
subclass of: Restriction
  on property: has start time
  on class: time of day
  max qualified cardinality: 1
definition: time period for which the starting time, ending time, and/or duration are required
note: As with 'time period', any one of {start time, end time, duration} may be omitted because the missing property can be inferred from the other two.

proper interval
type: Class
subclass of: time interval
source: https://www.w3.org/TR/owl-time/#time:ProperInterval
disjoint with: time instant
definition: time interval with a non-zero extent or duration
note: Proper interval is included explicitly to enable mapping to the same term in the Time Ontology in OWL for use with the Allen intervals encoded therein.

temporal entity
type: Class
definition: time interval or instant

time instant
type: Class
subclass of: temporal entity
definition: temporal entity that is a member of a time scale, with no extent or duration
example: The Battle of Hastings was on '14 October 1066'. (This gives the Julian date of the battle at a granularity of 'day'. If desired, the battle could be given more precisely as a time period within that calendar day.)
note: For scales that have a granularity specified in days, a date is a time point; for scales down to the seconds, the equivalent of an xsd:dateTime or xsd:dateTimeStamp is a time point.
note: The duration of each time interval that is an instance of the time point is the granularity of the time scale of the time point.
adapted from: https://www.omg.org/spec/DTV/
adapted from: https://www.w3.org/TR/owl-time/#time:Instant
synonym: instant in time
synonym: time point

time interval
type: Class
subclass of: temporal entity
definition: segment of the time axis, a location in time, with an extent or duration
example: the day whose Gregorian calendar date is September 11, 2001
example: the lifetime of Henry V
note: Every time interval has a beginning, an end, and a duration, even if not known. Every time interval is 'finite', a bounded segment of the time axis. The beginning or end of a time interval may be defined by reference to events that occur for a time interval that is not known.
note: Time intervals may be indefinite, meaning that their beginning is primordiality or their end is perpetuity, or both (eternity). This vocabulary assumes that indefinite time intervals exist and have some duration, but their duration is unknown.
adapted from: https://www.omg.org/spec/DTV/
adapted from: https://www.w3.org/TR/owl-time/#time:Interval

time of day
type: Class
subclass of: time instant
subclass of: Restriction
  on property: has time value
  on data range: string
  qualified cardinality: 1
definition: explicit time, according to a clock
note: The representation similar to xsd:dateTime, but should exclude the date component and time zone. The value of the has time value property roughly corresponds to xsd:time in XML schema datatypes, which is prohibited from use in OWL due to ambiguity in its definition.

time period
type: Class
subclass of: time interval
subclass of: Restriction
  on property: has duration
  on class: duration
  max qualified cardinality: 1
subclass of: Restriction
  on property: has end time
  on class: time of day
  max qualified cardinality: 1
subclass of: Restriction
  on property: has start time
  on class: time of day
  max qualified cardinality: 1
definition: time span over some finite window
note: A time period is defined by at least two of three properties: (1) a start time, (2) an end time, and (3) a duration. If more than one of these properties is missing, the time period may be invalid or unknown.
note: A time period is unknown if either the starting or ending time has no value. If a time period is unknown, then the duration should either be omitted or unknown (have no value).

has date
type: ObjectProperty
sub property of: has time
range: date
definition: identifies a calendar day, month and year

has date of issuance
type: ObjectProperty
type: FunctionalProperty
sub property of: has start date
range: date
definition: links something, such as an agreement, contract, license, or report, to the date it was made available

has date period
type: ObjectProperty
sub property of: has time
range: date period
definition: identifies a specific window of time, including a start date, end date and/or duration

has date time
type: ObjectProperty
sub property of: has time
range: date time
definition: identifies a specific date and time of day, possibly excluding the time zone

has date time stamp
type: ObjectProperty
sub property of: has time
range: date time stamp
definition: identifies a specific date and time of day, explicitly including the time zone

has date time stamp value
type: DatatypeProperty
range: dateTimeStamp
definition: specifies an actual literal (explicit) date and time, including the time zone

has date time value
type: DatatypeProperty
range: dateTime
definition: specifies an actual literal (explicit) date and time

has date value
type: DatatypeProperty
range: string
definition: specifies an actual literal (explicit) date captured in the format specified for xsd:date (i.e., ISO 8601 format), WITHOUT the time or timezone information; the semantics are identical to those of xsd:date
example: 2002-10-10 means October 10, 2002
note: In the Finance domain, for consistency with FpML (reference FpML Coding Schemes 30 June 2014, Version 1.56, section 2.1.1), the year MUST be specified as 4 digits, and the month and day MUST be specified as 2 digits with a leading zero if needed. Times and timezones should NOT be specified.

has duration
type: ObjectProperty
sub property of: has time
range: duration
definition: specifies the time during which something continues
note: This duration may be omitted or unknown if either the start or end Date of the DatePeriod is an ExplicitDate.

has duration value
type: DatatypeProperty
domain: duration
range: string
definition: specifies a literal (explicit) duration (amount of time) captured in the format specified for xsd:duration (i.e., ISO 8601 format); the semantics are identical to those of xsd:duration
example: -P3D means negative 3 days duration. This is used with OffsetDates to specify 3 days before (prior) to some other Date.
example: P1Y means 1 year
example: P1Y2M3DT4H5M6S means 1 year, 2 months, 3 days, 4 hours, 5 minutes, 6 seconds
example: P2M means 2 months
example: P3D means 3 days
example: PT4H means 4 hours
example: PT5M means 5 minutes
example: PT6S means 6 seconds
note: Negative durations are used to indicate relative dates that are before (rather than after) some other Date.

has end
type: ObjectProperty
sub property of: has time
range: time instant
definition: indicates the final or ending time point associated with something

has end date
type: ObjectProperty
sub property of: has date
sub property of: has end
range: date
definition: indicates the final or ending date associated with something

has end time
type: ObjectProperty
sub property of: has end
range: time of day
definition: indicates the final or ending time associated with something
usage note: Use of the property 'hasTimeValue' as a property of the TimeOfDay to record the actual time, or use either the DateTime or DateTimeStamp class with the date zeroed out if the date is not relevant but with the time included.

has explicit date
type: ObjectProperty
sub property of: has date
range: explicit date
definition: indicates a stated date, as opposed to a calculated or unknown date, associated with something

has observed date and time
type: DatatypeProperty
range: combined date time
definition: indicates a date and time associated with an event, measurement, record, or observation

has start
type: ObjectProperty
sub property of: has time
range: time instant
definition: indicates the initial time point associated with something

has start date
type: ObjectProperty
sub property of: has date
sub property of: has start
range: date
definition: indicates the initial date associated with something

has start time
type: ObjectProperty
sub property of: has start
range: time of day
definition: indicates the initial or starting time associated with something
usage note: Use of the property 'hasTimeValue' as a property of the TimeOfDay to record the actual time, or use either the DateTime or DateTimeStamp class with the date zeroed out if the date is not relevant but with the time included.

has time
type: ObjectProperty
range: temporal entity
definition: specifies a general time that can be associated with any element
note: This property corresponds to the property of the same name in the W3C Time Ontology, and can be used to support mapping.

has time period
type: ObjectProperty
sub property of: has time
range: time period
definition: identifies a specific window of time, including a starting time, ending time and/or duration

has time value
type: DatatypeProperty
range: string
definition: specifies an explicit time, captured in the format specified for xsd:time (i.e., ISO 8601 format), WITHOUT the date or timezone information

precedes
type: ObjectProperty
source: ISO 1087 Terminology work and terminology science - Vocabulary, Second edition, 2019-09, clause 3.2.24
definition: associates based on prior spatial or temporal proximity; occurs before in a logical order or sequence

succeeds
type: ObjectProperty
source: ISO 1087 Terminology work and terminology science - Vocabulary, Second edition, 2019-09, clause 3.2.24
inverse of: precedes
definition: associates based on subsequent spatial or temporal proximity; follows in a logical order or sequence