As per the rules, a worker is entitled to 21 days leave on the completion of 1 year of service. In sending you home before completion of your 1 year in service, the HR people of your company will save the company from paying for the 21 days. It's one of the things done in some companies. If you leave on October 31, you will not be entitled to 21 days benefits as you will not have completed 1 year of service.