Index: openacs-4/packages/acs-datetime/tcl/acs-datetime-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-datetime/tcl/acs-datetime-procs.tcl,v
diff -u -N -r1.19.2.4 -r1.19.2.5
--- openacs-4/packages/acs-datetime/tcl/acs-datetime-procs.tcl	19 Aug 2020 15:05:34 -0000	1.19.2.4
+++ openacs-4/packages/acs-datetime/tcl/acs-datetime-procs.tcl	19 Aug 2020 15:07:41 -0000	1.19.2.5
@@ -297,6 +297,7 @@
         incr year
         set month 01
     } else {
+        scan $month %d month
         incr month
     }
 
@@ -320,6 +321,7 @@
         set year [expr {$year - 1}]
         set month 12
     } else {
+        scan $month %d month
         set month [expr {$month - 1}]
     }