To create a recurring appointment second to last day of every month in Outlook calendar, please do as follows:

1. In the Calendar view, please click Home > New Appointment to create a new appointment.

2. In the opening Appointment window, please click Appointment > Recurrence. See screenshot:

3. Now the Appointment Recurrence dialog box comes out, please do as follows:

(1) In the Appointment time section, please add start time, end time, and duration as you need;
(2) In the Recurrence pattern section, please check the Monthly option, and then specify The last day of every 1 month(s) option or The last weekday of every 1 month(s) in the right section;
(3) Please specify the recurrence range for the appointment series;
(4) Click the OK button.

4. Now you return to the Appointment Series window, please select 1 day from the Reminder drop down list in the Options group on the Appointment Series tab. See screenshot:

5. Please add subject and location, compose appointment note, and then click Appointment Series > Save & Close.

So far, you have created a recurring appointment that will remind you on the second to the last day/weekday of every month in Outlook calendar.

Create a bi-weekly/fortnightly recurring meeting in Outlook

Create a quarterly recurring appointment in Outlook

Create a recurring meeting on 1st and 3rd Wednesday of every month

Create a meeting recurring every other day excluding weekends