def before_nearest_workday(dt):
    return previous_workday(nearest_workday(dt))
Tries to figure out the OS version used and returns
dataset/ETHPy150Open pydata/pandas/pandas/tseries/holiday.py/before_nearest_workday--crossover with--dataset/ETHPy150Open babble/babble/include/jython/Lib/platform.py/_syscmd_ver