DatetimeIndex objects are created at various frequencies by using passing frequency strings such as 'M', 'W', and 'BM' using the freq parameter of pd.date_range(). Under the hood, these frequency strings are translated into an instance of the pandas DateOffset object.
A DateOffset represents a regular frequency increment. Specific date offset logic, such as "month", "business day", or "hour", is represented in pandas with various subclasses of DateOffset. A DateOffset provides pandas with the intelligence to be able to determine how to calculate a specific interval of time from a reference date and time. This provides the user of pandas much greater flexibility in representing date/time offsets ...
