FHIR Extensions Pack
5.4.0 - May 2026 International flag

FHIR Extensions Pack, published by HL7 International / FHIR Infrastructure. This guide is not an authorized publication; it is the continuous build for version 5.4.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/fhir-extensions/ and changes regularly. See the Directory of published versions

Extension: Days of cycle

Official URL: http://hl7.org/fhir/StructureDefinition/timing-daysOfCycle Version: 5.4.0
Standards status: Trial-use Maturity Level: 3 Computable Name: DaysOfCycle
Other Identifiers: OID:2.16.840.1.113883.4.642.5.1527

Days of a possibly repeating cycle on which the action is to be performed. The cycle is defined by the first action with a timing element that is a parent of the daysOfCycle.

Context of Use

This extension may be used on the following element(s)

Usage info

Usages:

You can also check for usages in the FHIR IG Statistics

Changes since version 5.3.0:

  • No changes

    • Formal Views of Extension Content

    Description of Profiles, Differentials, Snapshots, and how the XML and JSON presentations work.

    This structure is derived from Extension

    Summary

    Complex Extension: Days of a possibly repeating cycle on which the action is to be performed. The cycle is defined by the first action with a timing element that is a parent of the daysOfCycle.

    • day: integer: An integer that specifies a day on which the action is to be performed (starting at one). In most cases, the first day of the first cycle will be day 1.

    Maturity: 3

    This structure is derived from Extension

    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..1 Extension Days on which the action should be performed
    Extension.Slices for extension Content/Rules for all slices
    Extension.Slices for extension.extension:day 1..* Extension What day to perform
    Extension.Slices for extension.extension:day.extension 0..0 Extension
    Extension.Slices for extension.extension:day.url 1..1 uri "day"
    Extension.Slices for extension.extension:day.value[x] 1..1 integer Value of extension
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/timing-daysOfCycle"
    Extension.value[x] 0..0 Value of extension

    doco Documentation for this format
    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..1 Extension Days on which the action should be performed
    Extension.id 0..1 id Unique id for inter-element referencing
    Extension.Slices for extension 1..* Extension Additional content defined by implementations
    Slice: Unordered, Open by value:url
    Extension.Slices for extension.extension:day 1..* Extension What day to perform
    Extension.Slices for extension.extension:day.id 0..1 id Unique id for inter-element referencing
    Extension.Slices for extension.extension:day.extension 0..0 Extension
    Slice: Unordered, Open by value:url

    Slicing Note: The rules on this element (including its children) apply to all the slices, but are not repeated in them
    Extension.Slices for extension.extension:day.url 1..1 uri "day"
    Extension.Slices for extension.extension:day.value[x] 1..1 integer Value of extension
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/timing-daysOfCycle"

    doco Documentation for this format

    This structure is derived from Extension

    Summary

    Complex Extension: Days of a possibly repeating cycle on which the action is to be performed. The cycle is defined by the first action with a timing element that is a parent of the daysOfCycle.

    • day: integer: An integer that specifies a day on which the action is to be performed (starting at one). In most cases, the first day of the first cycle will be day 1.

    Maturity: 3

    Differential View

    This structure is derived from Extension

    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..1 Extension Days on which the action should be performed
    Extension.Slices for extension Content/Rules for all slices
    Extension.Slices for extension.extension:day 1..* Extension What day to perform
    Extension.Slices for extension.extension:day.extension 0..0 Extension
    Extension.Slices for extension.extension:day.url 1..1 uri "day"
    Extension.Slices for extension.extension:day.value[x] 1..1 integer Value of extension
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/timing-daysOfCycle"
    Extension.value[x] 0..0 Value of extension

    doco Documentation for this format

    Snapshot View

    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..1 Extension Days on which the action should be performed
    Extension.id 0..1 id Unique id for inter-element referencing
    Extension.Slices for extension 1..* Extension Additional content defined by implementations
    Slice: Unordered, Open by value:url
    Extension.Slices for extension.extension:day 1..* Extension What day to perform
    Extension.Slices for extension.extension:day.id 0..1 id Unique id for inter-element referencing
    Extension.Slices for extension.extension:day.extension 0..0 Extension
    Slice: Unordered, Open by value:url

    Slicing Note: The rules on this element (including its children) apply to all the slices, but are not repeated in them
    Extension.Slices for extension.extension:day.url 1..1 uri "day"
    Extension.Slices for extension.extension:day.value[x] 1..1 integer Value of extension
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/timing-daysOfCycle"

    doco Documentation for this format

     

    Other representations of profile: CSV, Excel, Schematron

    Constraints

    Id Grade Path(s) Description Expression
    ele-1 error **ALL** elements All FHIR elements must have a @value or children hasValue() or (children().count() > id.count())
    ext-1 error **ALL** extensions Must have either extensions or value[x], not both extension.exists() != value.exists()

    R4B

    The extension is represented a little differently in R4B:

    • Remove the extension context RequestOrchestration.action (not for this version)
    • Remove the extension context RequestOrchestration.action.action (not for this version)
    • Note: Extensions that have been modified for R4B are still draft while real-world experience is collected
    Name Flags Card. Type Description & Constraints      Filter: doco
    Extension 0..1 Extension Days on which the action should be performed
    Extension. Slices for extension Content/Rules for all slices
    Extension.Slices for extension. extension:day 1..* Extension What day to perform
    Extension.Slices for extension.extension:day. extension 0 .. 0 Extension
    Extension.Slices for extension.extension:day. url 1 .. 1 uri "day"
    Extension.Slices for extension.extension:day. value[x] 1.. 1 integer Value of extension
    Extension. url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/timing-daysOfCycle"
    Extension. value[x] 0 .. 0 Value of extension

    doco Documentation for this format

    R4

    The extension is represented a little differently in R4:

    • Remove the extension context RequestOrchestration.action (not for this version)
    • Remove the extension context RequestOrchestration.action.action (not for this version)
    • Note: Extensions that have been modified for R4 are still draft while real-world experience is collected
    Name Flags Card. Type Description & Constraints      Filter: doco
    Extension 0..1 Extension Days on which the action should be performed
    Extension. Slices for extension Content/Rules for all slices
    Extension.Slices for extension. extension:day 1..* Extension What day to perform
    Extension.Slices for extension.extension:day. extension 0 .. 0 Extension
    Extension.Slices for extension.extension:day. url 1 .. 1 uri "day"
    Extension.Slices for extension.extension:day. value[x] 1.. 1 integer Value of extension
    Extension. url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/timing-daysOfCycle"
    Extension. value[x] 0 .. 0 Value of extension

    doco Documentation for this format

    R3

    The extension is represented a little differently in R3:

    • Remove the extension context RequestOrchestration.action (not for this version)
    • Remove the extension context RequestOrchestration.action.action (not for this version)
    • Note: Extensions that have been modified for R3 are still draft while real-world experience is collected
    Name Flags Card. Type Description & Constraints      Filter: doco
    Extension 0..1 Extension Days on which the action should be performed
    Extension. Slices for extension Content/Rules for all slices
    Extension.Slices for extension. extension:day 1..* Extension What day to perform
    Extension.Slices for extension.extension:day. extension 0 .. 0 Extension
    Extension.Slices for extension.extension:day. url 1 .. 1 uri "day"
    Extension.Slices for extension.extension:day. value[x] 1.. 1 integer Value of extension
    Extension. url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/timing-daysOfCycle"
    Extension. value[x] 0 .. 0 Value of extension

    doco Documentation for this format

    Search Parameters for this Extension

    (none found)