The time available for a made affirmative instrument to be approved by the House(s). The approval period is defined in legislation as how long the House had to act, often 28 or 40 calendar days, from the day they are made (signed into law). During the approval period instruments can be revoked, while procedure concludes at that point it does not affect the approval period end date.
Please check with JO what the dates are as they can differ from the norm - normally 28/40 days but can be longer/shorter depending on what the SI states and in some cases these steps are not needed.