DOC: solidify date conversion

jklymak · jklymak · commit eae20da250c1 · 2023-09-23T17:37:34.000-07:00
diff --git a/doc/api/next_api_changes/removals/26852-OG.rst b/doc/api/next_api_changes/removals/26852-OG.rst
@@ -2,10 +2,11 @@
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 ... of the `.dates` module are removed without replacements. These were
-undocumented and not exported.  Julian dates in Matplotlib were calculated from the
-Julian date epoch:
-``jdate = (date - np.datetime64('-4713-11-24T12:00')) / np.timedelta64(1, 'D')``,
-A Julian date was converted to datetime as
-``date = np.timedelta64(int(jdate * 24 * 3600), 's') + np.datetime64('-4713-11-24T12:00')``.
-where some care needs to be taken with the accuracy of the ``timedelta64``.  Given the various
-definitions of Julian date, users should exercise caution using these values.
+undocumented and not exported.
+
+Julian dates in Matplotlib were calculated from a Julian date epoch: ``jdate =
+(date - np.datetime64(EPOCH)) / np.timedelta64(1, 'D')``.  Conversely, a Julian
+date was converted to datetime as ``date = np.timedelta64(int(jdate * 24 *
+3600), 's') + np.datetime64(EPOCH)``. Matplotlib was using
+`EPOCH='-4713-11-24T12:00'` so that 2000-01-01 at 12:00 is 2_451_545.0 (see
+<https://en.wikipedia.org/wiki/Julian_day>`).
