Issue #10138: Removed 'indefinitely' from the proleptic calendar description.
diff --git a/Doc/library/calendar.rst b/Doc/library/calendar.rst
index 4ebe616..2e03946 100644
--- a/Doc/library/calendar.rst
+++ b/Doc/library/calendar.rst
@@ -16,7 +16,7 @@
functionality, see also the :mod:`datetime` and :mod:`time` modules.
Most of these functions and classes rely on the :mod:`datetime` module which
-uses an idealized calendar, the current Gregorian calendar indefinitely extended
+uses an idealized calendar, the current Gregorian calendar extended
in both directions. This matches the definition of the "proleptic Gregorian"
calendar in Dershowitz and Reingold's book "Calendrical Calculations", where
it's the base calendar for all computations.