How is "y_return" calculated ?

Sorry, i am having trouble getting the y_return in your "fundamental_final_table.xlsx".

The main confusion is whether y_return is calculated based on the quarter after the earning's report? (e.g we have fundamental data for Q1 (m1-m3), and y_return is calculated on Q2 m4-m6) or it is the 3-month span starting with the trade date, as mentioned in the paper, there is usually a two-month delay. (e.g apple reported their 2017 Q1 earning at 05/02, and the trade date is 06/01, y_return is calculated on the period from 06/01 to 08/31)?

I guess the second option makes more sense?