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# numpy.is_busday

`numpy.``is_busday`(dates, weekmask='1111100', holidays=None, busdaycal=None, out=None)

  Calculates which of the given dates are valid days, and which are not.

  New in version 1.7.0.

  Parameters : | dates : array_like of datetime64[D] The array of dates to process. weekmask : str or array_like of bool, optional A seven-element array indicating which of Monday through Sunday are valid days. May be specified as a length-seven list or array, like [1,1,1,1,1,0,0]; a length-seven string, like ‘1111100’; or a string like “Mon Tue Wed Thu Fri”, made up of 3-character abbreviations for weekdays, optionally separated by white space. Valid abbreviations are: Mon Tue Wed Thu Fri Sat Sun holidays : array_like of datetime64[D], optional An array of dates to consider as invalid dates. They may be specified in any order, and NaT (not-a-time) dates are ignored. This list is saved in a normalized form that is suited for fast calculations of valid days. busdaycal : busdaycalendar, optional A `busdaycalendar` object which specifies the valid days. If this parameter is provided, neither weekmask nor holidays may be provided. out : array of bool, optional If provided, this array is filled with the result.
  Returns : | out : array of bool An array with the same shape as `dates`, containing True for each valid day, and False for each invalid day.

  See also

  `busdaycalendar`
    An object that specifies a custom set of valid days.
  `busday_offset`
    Applies an offset counted in valid days.
  `busday_count`
    Counts how many valid days are in a half-open date range.

  Examples

      >>> # The weekdays are Friday, Saturday, and Monday
      ... np.is_busday(['2011-07-01', '2011-07-02', '2011-07-18'],
      ...                 holidays=['2011-07-01', '2011-07-04', '2011-07-17'])
      array([False, False,  True], dtype='bool')