<status value="active"/> <experimental value="true"/> <date value="2026-03-13T11:04:57+00:00"/> <publisher value="HL7/FO"/> <contact> <name value="HL7/FO"/> <telecom> <system value="url"/> <value value="http://www.hl7.org"/> </telecom> </contact> <description value="Code system of concepts used to describe acceptable start and end times, as well as days of the week, for appointment or resource scheduling. Used in HL7 Version 2.x messaging in the SCV and APR segments."/> <copyright value="HL7 Inc., 2026"/> <caseSensitive value="false"/> <compositional value="false"/> <content value="complete"/> <property> <code value="versionIntroduced"/> <uri value="http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#versionIntroduced"/> <description value="version when was this code introduced"/> <type value="string"/> </property> <property> <code value="versionDeprecated"/> <uri value="http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#versionDeprecated"/> <description value="version when was this code deprecated"/> <type value="string"/> </property> <property> <code value="status"/> <uri value="http://hl7.org/fhir/concept-properties#status"/> <description value="A code that indicates the status of the concept. Typical values are active, experimental, deprecated, and retired"/> <type value="code"/> </property> <property> <code value="comment"/> <uri value="http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#comment"/> <description value="A string that provides additional detail pertinent to the use or understanding of the concept"/> <type value="string"/> </property> <property> <code value="usage"/> <uri value="http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#usage"/> <description value="usage notes for this code"/> <type value="string"/> </property> <property> <code value="modified"/> <uri value="http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#modified"/> <description value="date of last modification"/> <type value="dateTime"/> </property> <concept id="2967"> <code value="Fri"/> <display value="An indicator that Friday is or is not preferred for the day on which the appointment will occur."/> <definition value="An indicator that Friday is or is not preferred for the day on which the appointment will occur."/> <property> <code value="comment"/> <valueString value="In component 2, specify OK or NO.<p>OK = Preferred appointment day NO = Day is not preferred"/> </property> <property> <code value="modified"/> <valueDateTime value="2015-07-13"/> </property> <property> <code value="versionIntroduced"/> <valueString value="2.4"/> </property> </concept> <concept id="2959"> <code value="Mon"/> <display value="An indicator that Monday is or is not preferred for the day on which the appointment will occur."/> <definition value="An indicator that Monday is or is not preferred for the day on which the appointment will occur."/> <property> <code value="comment"/> <valueString value="In component 2, specify OK or NO.<p>OK = Preferred appointment day NO = Day is not preferred"/> </property> <property> <code value="modified"/> <valueDateTime value="2015-07-13"/> </property> <property> <code value="versionIntroduced"/> <valueString value="2.4"/> </property> </concept> <concept id="2957"> <code value="Prefend"/> <display value="An indicator that there is a preferred end time for the appointment request, service or resource."/> <definition value="An indicator that there is a preferred end time for the appointment request, service or resource."/> <property> <code value="comment"/> <valueString value="In component 2, specify any valid time in the format HHMM, using 24-hour clock notation where HH = hour and MM = minutes"/> </property> <property> <code value="modified"/> <valueDateTime value="2015-07-13"/> </property> <property> <code value="versionIntroduced"/> <valueString value="2.4"/> </property> </concept> <concept id="2955"> <code value="Prefstart"/> <display value="An indicator that there is a preferred start time for the appointment request, service or resource."/> <definition value="An indicator that there is a preferred start time for the appointment request, service or resource."/> <property> <code value="comment"/> <valueString value="In component 2, specify any valid time in the format HHMM, using 24-hour clock notation where HH = hour and MM = minutes"/> </property> <property> <code value="modified"/> <valueDateTime value="2015-07-13"/> </property> <property> <code value="versionIntroduced"/> <valueString value="2.4"/> </property> </concept> <concept id="2969"> <code value="Sat"/> <display value="An indicator that Saturday is or is not preferred for the day on which the appointment will occur."/> <definition value="An indicator that Saturday is or is not preferred for the day on which the appointment will occur."/> <property> <code value="comment"/> <valueString value="In component 2, specify OK or NO.<p>OK = Preferred appointment day NO = Day is not preferred"/> </property> <property> <code value="modified"/> <valueDateTime value="2015-07-13"/> </property> <property> <code value="versionIntroduced"/> <valueString value="2.4"/> </property> </concept> <concept id="2971"> <code value="Sun"/> <display value="An indicator that Sunday is or is not preferred for the day on which the appointment will occur."/> <definition value="An indicator that Sunday is or is not preferred for the day on which the appointment will occur."/> <property> <code value="comment"/> <valueString value="In component 2, specify OK or NO.<p>OK = Preferred appointment day NO = Day is not preferred"/> </property> <property> <code value="modified"/> <valueDateTime value="2015-07-13"/> </property> <property> <code value="versionIntroduced"/> <valueString value="2.4"/> </property> </concept> <concept id="2965"> <code value="Thu"/> <display value="An indicator that Thursday is or is not preferred for the day on which the appointment will occur."/> <definition value="An indicator that Thursday is or is not preferred for the day on which the appointment will occur."/> <property> <code value="comment"/> <valueString value="In component 2, specify OK or NO.<p>OK = Preferred appointment day NO = Day is not preferred"/> </property> <property> <code value="modified"/> <valueDateTime value="2015-07-13"/> </property> <property> <code value="versionIntroduced"/> <valueString value="2.4"/> </property> </concept> <concept id="2961"> <code value="Tue"/> <display value="An indicator that Tuesday is or is not preferred for the day on which the appointment will occur."/> <definition value="An indicator that Tuesday is or is not preferred for the day on which the appointment will occur."/> <property> <code value="comment"/> <valueString value="In component 2, specify OK or NO.<p>OK = Preferred appointment day NO = Day is not preferred"/> </property> <property> <code value="modified"/> <valueDateTime value="2015-07-13"/> </property> <property> <code value="versionIntroduced"/> <valueString value="2.4"/> </property> </concept> <concept id="2963"> <code value="Wed"/> <display value="An indicator that Wednesday is or is not preferred for the day on which the appointment will occur."/> <definition value="An indicator that Wednesday is or is not preferred for the day on which the appointment will occur."/> <property> <code value="comment"/> <valueString value="In component 2, specify OK or NO.<p>OK = Preferred appointment day NO = Day is not preferred"/> </property> <property> <code value="modified"/> <valueDateTime value="2015-07-13"/> </property> <property> <code value="versionIntroduced"/> <valueString value="2.4"/> </property> </concept> </CodeSystem>