Time Setting - Tertial date formatting
Probably the best way to do this is use a combination of both "Real Time" and "Fake Time". Have all of your calculations be in real time, but use the Fake Time list for all dashboarding/UI presentations. In order to do this, create your fake time list which mirrors your real time (all the months with the same name), but instead of 4 quarters, you have 3. Then have a mapping module mapping real time (months) to the fake time months. Then, with fake time, it is just an aggregation of the fake months to the 3 parents.
Hope this helps,
Perfect, thanks @rob_marshall !0