'Filters for releases that are on or after each simulation date and
determines the next quarter by picking out the upcoming release for
each date in the index.
Parameters
stacked_last_per_qtr : pd.DataFrame
A DataFrame with index of calendar dates, sid, and normalized
quarters with each row being the latest estimate for the row\'s
index values, sorted by event date.
Returns
next_releases_per_date_index : pd.MultiIndex
An index of calendar dates, sid, and normalized quarters, for only
the rows that have a next event.'

def get_zeroth_quarter_idx(self, stacked_last_per_qtr):

    next_releases_per_date = stacked_last_per_qtr.loc[(stacked_last_per_qtr[EVENT_DATE_FIELD_NAME] >= stacked_last_per_qtr.index.get_level_values(SIMULATION_DATES))].groupby(level=[SIMULATION_DATES, SID_FIELD_NAME], as_index=False).nth(0)
    return next_releases_per_date.index
