How do historical lookback windows work?

Personas allows you to compute new traits and audiences of your users based on their entire customer journey, and all historical data you’ve tracked with Segment.

When you create a new computed trait or audience, you include a lookback window that determines how far back into the past the trait or audiences will be computed.

Some important things to keep in mind when setting a lookback window:

  • Historical lookback windows are based on the event timestamp field.

  • Lookback windows are precise down to the hour, so a 90-day lookback window will include any events with a timestamp timestamp within the last 2,160 hours (24 hr/day * 90 days).

  • The trait and audience will automatically update going forward as historical events exceed the lookback window.


If you have any questions or see anywhere we can improve our documentation, please let us know or kick off a conversation in the Segment Community!