def next_monday_or_tuesday(dt):
    dow = dt.weekday()
    if dow == 5 or dow == 6:
        return dt + timedelta(2)
    elif dow == 0:
        return dt + timedelta(1)
    return dt
For second holiday of two adjacent ones!
dataset/ETHPy150Open pydata/pandas/pandas/tseries/holiday.py/next_monday_or_tuesday