I need to set the recurrence on an item to be once per quarter. I can't seem to find the syntax for it.
Unfortunately, all dates that include "month" are currently being treated as "30 days" so a task due "every 3 months" for example will work exactly as "every 30 days".
We'll look into changing in the future so it will use the correct day count, but for now, as a workaround, the best option for quarterly tasks would be to set up 4 different tasks with the same name, set one to "every 30 Sep", the other one to "ev 30 Nov" and so on. Each will correctly be rescheduled for the next year, but as the date approaches, you will only see the one in the 7 days view and so forth.