PEP 410: drop int type, add an argument against the datetime type

pep-0410.txt

@@ -53,9 +53,8 @@ Add a *timestamp* optional argument to:
  * time module: clock(), clock_gettime(), clock_getres(), time() and
    wallclock()
 
-The *timestamp* argument is a type, there are three supported types:
+The *timestamp* argument is a type, there are two supported types:
 
- * int
  * float
  * decimal.Decimal
 
@@ -68,7 +67,8 @@ precision) in functions having timestamp arguments:
  * time.gmtime(), time.localtime()
  * os.utimensat(), os.futimens()
 
-The os.stat_float_times() is deprecated: use timestamp=int argument instead.
+The os.stat_float_times() is deprecated: use an explicit cast using int()
+instead.
 
 .. note::
    The decimal module is implemented in Python and is slow, but there is a C
@@ -123,6 +123,9 @@ with the Python license.
 datetime.datetime
 -----------------
 
+Most functions returning timestamps don't have a known starting point or
+timezone information, and so cannot be converted to datetime.datetime.
+
 datetime.datetime only supports microsecond resolution, but can be enhanced
 to support nanosecond.