Part eight of an event sourcing series covering bi-temporal event sourcing fundamentals. Explains why two timestamps are needed — an application timestamp (when the event entered the system) and an effective timestamp (when it takes effect) — enabling queries against past, present, or future states. Introduces the concept of timelines as a projection mechanism built from bi-temporal event streams, covering sort ordering (effective time first, application time as tiebreaker), granularity differences between the two timestamps, and a concrete F# code example using a TimelineProjector with organisation chart events.
Table of contents
Why do we need application and effective timestamps?TimelinesDifferent granularityBi-temporal projectionTo sum upDeep Dive633 Impressions