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
Lookback windows are precise down to the hour, so a 90-day lookback window will include any events with a
timestamptimestamp 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.