PEP 410: rephrase doc about datetime.datetime and datetime.timedelta

pep-0410.txt

@@ -126,14 +126,15 @@ datetime.datetime
 datetime.datetime only supports microsecond resolution, but can be enhanced
 to support nanosecond.
 
-datetime.datetime has issues:
+datetime.datetime has issues with timezone. For example, a datetime object
+without timezone and a datetime with a timezone cannot be compared.
 
-- there is no easy way to convert it into "seconds since the epoch"
-- any broken-down time has issues of time stamp ordering in the
-  duplicate hour of switching from DST to normal time
-- time zone support is flaky-to-nonexistent in the datetime module
+datetime.datetime has ordering issues with daylight saving time (DST) in the
+duplicate hour of switching from DST to normal time.
 
-datetime.datetime is also more complex than a simple number.
+datetime.datetime is not as well integrated than Epoch timestamps, some
+functions don't accept this type as input. For example, os.utime() expects a
+tuple of Epoch timestamps.
 
 datetime.timedelta
 ------------------
@@ -141,10 +142,9 @@ datetime.timedelta
 As datetime.datetime, datetime.timedelta only supports microsecond resolution,
 but can be enhanced to support nanosecond.
 
-Even if datetime.timedelta have most criteria, it was not selected because it
-is more complex than a simple number and is not accepted by functions getting
-timestamp inputs.
-
+datetime.timedelta is not as well integrated than Epoch timestamps, some
+functions don't accept this type as input. For example, os.utime() expects a
+tuple of Epoch timestamps.
 
 .. _tuple-integers: