rok commented on a change in pull request #10176:
URL: https://github.com/apache/arrow/pull/10176#discussion_r645447571
##########
File path: docs/source/cpp/compute.rst
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@@ -637,6 +637,55 @@ String extraction
e.g. 'letter' and 'digit' for the regular expression
``(?P<letter>[ab])(?P<digit>\\d)``.
+Temporal component extraction
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+These functions extract datetime components (year, month, day, etc) from
timestamp type.
+Note: timezone information is currently ignored if present.
+
++--------------------+------------+-------------------+-----------------+--------+
+| Function name | Arity | Input types | Output type |
Notes |
++====================+============+===================+=================+========+
+| year | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| month | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| day | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| day_of_week | Unary | Temporal | Numeric | \(1)
|
++--------------------+------------+-------------------+-----------------+--------+
+| day_of_year | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| iso_year | Unary | Temporal | Numeric | \(2)
|
++--------------------+------------+-------------------+-----------------+--------+
+| iso_week | Unary | Temporal | Numeric | \(2)
|
++--------------------+------------+-------------------+-----------------+--------+
+| iso_calendar | Unary | Temporal | Scalar Struct | \(3)
|
++--------------------+------------+-------------------+-----------------+--------+
+| quarter | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| hour | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| minute | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| second | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| millisecond | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| microsecond | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| nanosecond | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+| subsecond | Unary | Temporal | Numeric |
|
++--------------------+------------+-------------------+-----------------+--------+
+
+* \(1) Outputs the number of the day of the week. Week begins on Monday and is
denoted
+ by 0 and ends on Sunday denoted by 6.
+* \(2) First ISO week has the majority (4 or more) of it's days in January.
ISO year
+ starts with the first ISO week.
+ See `ISO 8601 week date definition`_ for more details.
+* \(3) Output is a ``{"iso_year": output type, "iso_week": output type,
"day_of_week": output type}`` Struct.
+.. _ISO 8601 week date definition:
https://en.wikipedia.org/wiki/ISO_week_date#First_week
Review comment:
Sounds like a good idea!
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