In the CrossEngage CDP, the segments are calculated every time that they are in use. This means that your segmentation will always be up to date, representing the state of the users/events that are available in the very moment the segment is used.
This means that as your customer data is constantly changing and the relative time-phrase evaluation always is dependent on the query time, the segment size will differ from calculation to calculation.
To clarify the evaluation triggers/schedules, please find below a list of all operations accessing our segmentation module.
In this case the amount of users is representing the state of the very moment of segment editing. This means throughout editing, the segment size is calculated instantaneous.
In the case of an audience campaign, the segment is evaluated at the scheduled time of dispatch. This applies to one time as well as recurring campaigns(e.g. recurring birthday campaigns scheduled to run each day will evaluate/refresh the segmentation every time the campaign is dispatched to ensure only the correct users are contacted).
For a story, the Segment is evaluated every time a user reaches a segmentation block.
For a realtime-campaign, the segmentation criteria is filtered for each user as soon as this user fulfils all journey steps, making them eligible to receive a message.