Update datetime usage docs

docs/usage/types/datetime.md

@@ -2,85 +2,50 @@
 description: Support for datetime types.
 ---
 
-*Pydantic* supports the following [datetime](https://docs.python.org/library/datetime.html#available-types)
+Pydantic supports the following [datetime](https://docs.python.org/library/datetime.html#available-types)
 types:
 
-`datetime.date`
-: see [Datetime Types](#datetime-types) below for more detail on parsing and validation
+* `datetime.date`
+* `datetime.time`
+* `datetime.datetime`
+* `datetime.timedelta`
 
-`datetime.time`
-: see [Datetime Types](#datetime-types) below for more detail on parsing and validation
+## Validation of datetime types
 
-`datetime.datetime`
-: see [Datetime Types](#datetime-types) below for more detail on parsing and validation
-
-`datetime.timedelta`
-: see [Datetime Types](#datetime-types) below for more detail on parsing and validation
-
-`PastDate`
-: like `date`, but the date should be in the past
-
-`FutureDate`
-: like `date`, but the date should be in the future
-
-## Datetime types
-
-* `datetime` fields can be:
-
-  * `datetime`, existing `datetime` object
-  * `int` or `float`, assumed as Unix time, i.e. seconds (if >= `-2e10` and <= `2e10`) or milliseconds (if < `-2e10`or > `2e10`) since 1 January 1970
-  * `str`, following formats work:
+* `datetime` fields will accept values of type:
 
+  * `datetime`; an existing `datetime` object
+  * `int` or `float`; assumed as Unix time, i.e. seconds (if >= `-2e10` and <= `2e10`) or milliseconds
+    (if < `-2e10`or > `2e10`) since 1 January 1970
+  * `str`; the following formats are accepted:
     * `YYYY-MM-DD[T]HH:MM[:SS[.ffffff]][Z or [±]HH[:]MM]`
     * `int` or `float` as a string (assumed as Unix time)
 
-* `date` fields can be:
+* `date` fields will accept values of type:
 
-  * `date`, existing `date` object
-  * `int` or `float`, see `datetime`
-  * `str`, following formats work:
+  * `date`; an existing `date` object
+  * `int` or `float`; handled the same as described for `datetime` above
+  * `str`; the following formats are accepted:
 
     * `YYYY-MM-DD`
-    * `int` or `float`, see `datetime`
+    * `int` or `float` as a string (assumed as Unix time)
 
-* `time` fields can be:
+* `time` fields will accept values of type:
 
-  * `time`, existing `time` object
-  * `str`, following formats work:
+  * `time`; an existing `time` object
+  * `str`; the following formats are accepted:
 
     * `HH:MM[:SS[.ffffff]][Z or [±]HH[:]MM]`
 
-* `timedelta` fields can be:
+* `timedelta` fields will accept values of type:
 
-  * `timedelta`, existing `timedelta` object
-  * `int` or `float`, assumed as seconds
-  * `str`, following formats work:
+  * `timedelta`; an existing `timedelta` object
+  * `int` or `float`; assumed to be seconds
+  * `str`; the following formats are accepted:
 
     * `[-][DD ][HH:MM]SS[.ffffff]`
     * `[±]P[DD]DT[HH]H[MM]M[SS]S` ([ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) format for timedelta)
 
-
-## Pydantic date types
-
-`PastDate`
-: like `date`, but the date should be in the past
-
-`FutureDate`
-: like `date`, but the date should be in the future
-
-`AwareDatetime`
-: like `datetime`, but requires the value to have timezone info
-
-`NaiveDatetime`
-: like `datetime`, but requires the value to lack timezone info
-
-`PastDatetime`
-: like `datetime`, but the datetime should be in the past
-
-`FutureDatetime`
-: like `datetime`, but the datetime should be in the future
-
-
 ```py
 from datetime import date, datetime, time, timedelta
 
@@ -106,3 +71,26 @@ print(m.model_dump())
 {'d': datetime.date(2023, 3, 24), 'dt': datetime.datetime(2032, 4, 23, 10, 20, 30, 400000, tzinfo=TzInfo(+02:30)), 't': datetime.time(4, 8, 16), 'td': datetime.timedelta(days=3, seconds=45005)}
 """
 ```
+
+## Pydantic date types
+
+The following types can be imported from `pydantic`, and augment the types described above
+with additional validation constraints:
+
+`PastDate`
+: like `date`, with the constraint that the value must be in the past
+
+`FutureDate`
+: like `date`, with the constraint that the value must be in the future
+
+`PastDatetime`
+: like `PastDate`, but for `datetime`
+
+`FutureDatetime`
+: like `FutureDate`, but for `datetime`
+
+`AwareDatetime`
+: like `datetime`, with the constraint that the value must have timezone info
+
+`NaiveDatetime`
+: like `datetime`, with the constraint that the value must lack timezone info