Class QuarterBegin

xarray/coding/cftime_offsets.py:473–495

class QuarterBegin(QuarterOffset):
    # When converting a string to an offset, pandas converts
    # 'QS' to a QuarterBegin offset starting in the month of
    # January.  When creating a QuarterBegin offset directly
    # from the constructor, however, the default month is March.
    # We follow that behavior here.
    _default_month = 3
    _freq = "QS"
    _day_option = "start"

    def rollforward(self, date):
        """Roll date forward to nearest start of quarter"""
        if self.onOffset(date):
            return date
        else:
            return date + QuarterBegin(month=self.month)

    def rollback(self, date):
        """Roll date backward to nearest start of quarter"""
        if self.onOffset(date):
            return date
        else:
            return date - QuarterBegin(month=self.month)


class QuarterEnd(QuarterOffset):