As Per my understanding Clear Days meaning All the days in a schedule or in timeline, except the day of commencement and day of completion.
According to clear days meaning the day of sending of notice and day of meeting is excluded i.e. 2 days
according to act proxy form will be deliver to company before 48 hour from the meeting so 2 days for proxy form.
Now the total time period is 25 days
21days :- for notice
1 day :- sending for notice
1 day :- meeting
2 days :- for proxy form