Date Offset Classes
===================

.. currentmodule:: pandasCore

DateOffset classes represent regular frequency offsets for date arithmetic.

DateOffset
----------

Base class for date offsets.

.. code-block:: python

   import pandasCore as pd

   # Create offset
   offset = pd.DateOffset(days=1)

   # Add to timestamp
   ts = pd.Timestamp('2023-01-01')
   ts + offset  # 2023-01-02

Parameters
^^^^^^^^^^

.. list-table::
   :widths: 15 10 10 65
   :header-rows: 1

   * - Parameter
     - Type
     - Default
     - Description
   * - n
     - int
     - 1
     - Number of periods
   * - normalize
     - bool
     - False
     - Normalize to midnight
   * - years
     - int
     - 0
     - Years to add
   * - months
     - int
     - 0
     - Months to add
   * - weeks
     - int
     - 0
     - Weeks to add
   * - days
     - int
     - 0
     - Days to add
   * - hours
     - int
     - 0
     - Hours to add
   * - minutes
     - int
     - 0
     - Minutes to add
   * - seconds
     - int
     - 0
     - Seconds to add

Time Offsets
------------

.. list-table::
   :widths: 20 15 65
   :header-rows: 1

   * - Class
     - Alias
     - Description
   * - Day
     - D
     - One day
   * - Hour
     - H
     - One hour
   * - Minute
     - T, min
     - One minute
   * - Second
     - S
     - One second
   * - Milli
     - L, ms
     - One millisecond
   * - Micro
     - U, us
     - One microsecond
   * - Nano
     - N, ns
     - One nanosecond

Month Offsets
-------------

.. list-table::
   :widths: 25 15 60
   :header-rows: 1

   * - Class
     - Alias
     - Description
   * - MonthEnd
     - M
     - End of month
   * - MonthBegin
     - MS
     - Start of month
   * - BusinessMonthEnd
     - BM
     - Business month end
   * - BusinessMonthBegin
     - BMS
     - Business month start

Quarter Offsets
---------------

.. list-table::
   :widths: 25 15 60
   :header-rows: 1

   * - Class
     - Alias
     - Description
   * - QuarterEnd
     - Q
     - End of quarter
   * - QuarterBegin
     - QS
     - Start of quarter
   * - BQuarterEnd
     - BQ
     - Business quarter end
   * - BQuarterBegin
     - BQS
     - Business quarter start

Year Offsets
------------

.. list-table::
   :widths: 25 15 60
   :header-rows: 1

   * - Class
     - Alias
     - Description
   * - YearEnd
     - A, Y
     - End of year
   * - YearBegin
     - AS, YS
     - Start of year
   * - BYearEnd
     - BA, BY
     - Business year end
   * - BYearBegin
     - BAS, BYS
     - Business year start

Business Day Offsets
--------------------

.. list-table::
   :widths: 25 15 60
   :header-rows: 1

   * - Class
     - Alias
     - Description
   * - BusinessDay
     - B
     - Business day
   * - BusinessHour
     - BH
     - Business hour
   * - CustomBusinessDay
     - C
     - Custom business day

Common Methods
--------------

All offset classes support:

.. list-table::
   :widths: 30 70
   :header-rows: 1

   * - Method
     - Description
   * - apply(ts)
     - Apply offset to timestamp
   * - rollback(ts)
     - Roll back to previous period boundary
   * - rollforward(ts)
     - Roll forward to next period boundary
   * - is_on_offset(ts)
     - Check if timestamp is on offset
   * - copy()
     - Create copy of offset