Release dates
A release date describes a particular event with territory, edition and precision context rather than one universal timestamp for a work.
A film or album can be released through several events. A premiere, regional theatrical opening and later physical edition need not share one date.
Name the event before choosing the year
For an invented film:
| Event | Date | Context |
|---|---|---|
| Premiere | 2020-02-20 | Initial public presentation |
| Theatrical release | 2020-05-12 | One territory |
| Theatrical release | 2020-06-19 | Another territory |
| Physical edition | 2021-01-05 | Later distribution event |
A displayed year of 2020 and a physical-release year of 2021 can both be valid within their fields. They are not automatically competing identities.
TMDB's release-date interface provides event types and country context. In Emby, the displayed item date/year reflects the applicable source and selected field representation.
Preserve precision that is actually known
| Supplied information | What is known |
|---|---|
| 2020 | Year only |
| 2020-05 | Year and month |
| 2020-05-12 | Calendar day |
| A full timestamp with offset | A specified clock/instant relationship |
Substituting January 1 for a known year can make unknown precision look like a verified date. A library may use a sorting convention, but that convention should remain distinguishable from the source's claim.
These partial values illustrate metadata precision; they are not all complete RFC 3339 timestamps.
A calendar date and an instant differ
A release announced for a particular day can be a calendar-date relationship. A timestamp at midnight UTC describes an instant that may fall on another calendar day in another time zone.
Converting every date through a timestamp pipeline can therefore shift the displayed release day without improving the source fact. The field's data type and event meaning determine whether time-zone conversion is appropriate.
Sorting selects a relationship
Sorting by first release, local release, edition issue or date added can produce different useful sequences. Date added describes a library activity rather than a release event.
When two sources disagree, compare event, territory, edition and precision through conflicting metadata. Choosing a date with the right scope is more informative than forcing every record to agree on one year.