# pandas.tseries.offsets.DateOffset

class pandas.tseries.offsets.DateOffset

  Standard kind of date increment used for a date range.

  Works exactly like relativedelta in terms of the keyword args you pass in, use of the keyword n is discouraged– you would be better off specifying n in the keywords you use, but regardless it is there for you. n is needed for DateOffset subclasses.

  DateOffset work as follows. Each offset specify a set of dates that conform to the DateOffset. For example, Bday defines this set to be the set of dates that are weekdays (M-F). To test if a date is in the set of a DateOffset dateOffset we can use the is_on_offset method: dateOffset.is_on_offset(date).

  If a date is not on a valid date, the rollback and rollforward methods can be used to roll the date to the nearest valid date before/after the date.

  DateOffsets can be created to move dates forward a given number of valid dates. For example, Bday(2) can be added to a date to move it two business days forward. If the date does not start on a valid date, first it is moved to a valid date. Thus pseudo code is:

  def __add__(date):

    date = rollback(date) # does nothing if date is valid return date + <n number of periods>

  When a date offset is created for a negative number of periods, the date is first rolled forward. The pseudo code is:

  def __add__(date):

    date = rollforward(date) # does nothing is date is valid return date + <n number of periods>

  Zero presents a problem. Should it roll forward or back? We arbitrarily have it rollforward:

  date + BDay(0) == BDay.rollforward(date)

  Since 0 is a bit weird, we suggest avoiding its use.

  Parameters
    n int, default 1

      The number of time periods the offset represents.

    normalize bool, default False

      Whether to round the result of a DateOffset addition down to the previous midnight.

    **kwds

      Temporal parameter that add to or replace the offset value.

      Parameters that add to the offset (like Timedelta):

      - years

      - months

      - weeks

      - days

      - hours

      - minutes

      - seconds

      - microseconds

      - nanoseconds

      Parameters that replace the offset value:

      - year

      - month

      - day

      - weekday

      - hour

      - minute

      - second

      - microsecond

      - nanosecond.

  See also

  `dateutil.relativedelta.relativedelta`

    The relativedelta type is designed to be applied to an existing datetime an can replace specific components of that datetime, or represents an interval of time.

  Examples

      >>> from pandas.tseries.offsets import DateOffset
      >>> ts = pd.Timestamp('2017-01-01 09:10:11')
      >>> ts + DateOffset(months=3)
      Timestamp('2017-04-01 09:10:11')

      >>> ts = pd.Timestamp('2017-01-01 09:10:11')
      >>> ts + DateOffset(months=2)
      Timestamp('2017-03-01 09:10:11')

  Attributes

  `base` | Returns a copy of the calling offset object with n=1 and all other attributes equal.

  freqstr |
  kwds |
  n |
  name |
  nanos |
  normalize |
  rule_code |

  Methods

  `__call__`(*args, **kwargs) | Call self as a function.
  `rollback` | Roll provided date backward to next offset only if not on offset.
  `rollforward` | Roll provided date forward to next offset only if not on offset.

  apply |
  apply_index |
  copy |
  isAnchored |
  is_anchored |
  is_month_end |
  is_month_start |
  is_on_offset |
  is_quarter_end |
  is_quarter_start |
  is_year_end |
  is_year_start |
  onOffset |