By default, closing banners results in further banner displays being prevented for seven days. The thank you campaign will run for 21 days, so one has to close the banner up to three times during the campaign. Saying "Thank You" shouldn't be obtrusive, we want the duration of the cookie to be longer.

Acceptance Criteria

• The duration of the cookie that is stored when closing a banner is set to 21 days.

Notes

• see [different cn methods](https://github.com/wikimedia/mediawiki-extensions-CentralNotice/blob/fb993752cc3c1651e4f81e32384061fa5f58689e/resources/ext.centralNotice.display/index.js#L754-L768) to handle close events
  • the reason should still be close
  • duration is expected to be number of seconds