| # | Name | Source | Ver | Description | |
| 1 | Relative Date Criteria | hl7.fhir.uv.extensions.r4#1.0.0 | R4 | Specifies that a date is relative to some event. The event happens [Duration] after [Event]. | |
| 2 | Rendered Value | hl7.fhir.uv.extensions.r4#1.0.0 | R4 | Provides a rendered version of the value intended for human display. For example, a sensitive identifier (e.g. social security number) partially obscured by asterisks; a drivers licence number with dashes inserted; a date formatted as MMM dd, yyyy; etc. | |
| 3 | Timezone Code | hl7.fhir.uv.extensions.r4#1.0.0 | R4 | An IANA timezone code for the timezone offset per [BCP 175](https://www.iana.org/go/rfc6557). The offset is specified as part of a dateTime/instant (or using the tzOffset extension on a date if necessary). The timezone code may also be provided to allow for human display of the location associated with the offset. | |
| 4 | Timezone Offset | hl7.fhir.uv.extensions.r4#1.0.0 | R4 | Timezone offset, for dates where timezone is not allowed as part of the base date. | |
| 5 | Uncertain period | hl7.fhir.uv.extensions.r4#1.0.0 | R4 | Used to express an uncertain date(+time) value by specifying an allowed or observed upper and lower bound. |
| 1 | 2 | 3 | 4 | 5 | |
| Extension | C D | C D | C D | C D | C D |
| Extension.extension | S C D (5) | C | C | C | C |
| Extension.extension.value[x] | C B M (5) | ||||
| Extension.extension.url | F (5) | ||||
| Extension.extension.extension | C (5) | ||||
| Extension.url | F | F | F | F | F |
| Extension.value[x] | C | C | C B M | C | C |
Produced 06 Apr 2023