provide compat for construction of strings to numpy datetime64's with
    tz-changes in 1.11 that make '2015-01-01 09:00:00Z' show a deprecation
    warning, when need to pass '2015-01-01 09:00:00'

def np_datetime64_compat(s, *args, **kwargs):
    """
    provide compat for construction of strings to numpy datetime64's with
    tz-changes in 1.11 that make '2015-01-01 09:00:00Z' show a deprecation
    warning, when need to pass '2015-01-01 09:00:00'
    """
    s = tz_replacer(s)
    return np.datetime64(s, *args, **kwargs)