--- loncom/lonnet/perl/lonnet.pm	2021/05/10 16:08:40	1.1452
+++ loncom/lonnet/perl/lonnet.pm	2021/05/10 18:13:50	1.1453
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1452 2021/05/10 16:08:40 raeburn Exp $
+# $Id: lonnet.pm,v 1.1453 2021/05/10 18:13:50 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -8533,13 +8533,17 @@ sub allowed {
 # Locks might take effect only after 10 minutes cache expiration for other
 # courses, and 2 minutes for current course
 
-    my $envkey;
     if ($thisallowed=~/L/) {
-        foreach $envkey (keys(%env)) {
+        my $now = time;
+        foreach my $envkey (keys(%env)) {
            if ($envkey=~/^user\.role\.(st|ta)\.([^\.]*)/) {
                my $courseid=$2;
                my $roleid=$1.'.'.$2;
                $courseid=~s/^\///;
+               unless ($env{'request.role'} eq $roleid) {
+                   my ($start,$end) = split(/\./,$env{$envkey});
+                   next unless (($now >= $start) && (!$end || $end > $now));
+               }
                my $expiretime=600;
                if ($env{'request.role'} eq $roleid) {
 		  $expiretime=120;