I've set our sprints up to last for 2 weeks, nominally 10 days. Day 1 starts with planning and then moves to start development. Day 10 has S&T and Retro, but also cleans up the release/tidies the Boards/backlog etc.
It's now been suggested to me that a 10 day sprint should have 10 days of development, and then a deliberate 1 (or 2) day gap to be built in to allow the agile ceremonies etc.
Should there be a gap? Or should the sprint also contain the ceremonies?