We should not be relying on real time at all.

Here are some attempts to go into that direction

t/lock-expiration.t

@@ -14,9 +14,17 @@
 
 require 't/test.pl';
 package OddMuse;
-use Test::More tests => 19;
+use Test::More tests => 17;
 
-AppendStringToFile($ConfigFile, "\$SurgeProtection = 1;\n");
+# TODO move that to test.pl?
+# we will be using the same fake time in these tests as well
+BEGIN {
+  sub updateFakeTime { utime($_[0], $_[0], "$DataDir/ts") }
+  *CORE::GLOBAL::sleep = sub { updateFakeTime((stat("$DataDir/ts"))[9] + $_[0]) };
+  *CORE::GLOBAL::time  = sub { (stat("$DataDir/ts"))[9] };
+}
+
+# AppendStringToFile($ConfigFile, "\$SurgeProtection = 1;\n"); # why are we enabling it?
 $localhost = 'confusibombus';
 $ENV{'REMOTE_ADDR'} = $localhost;
 my $lock = $LockDir . 'visitors';
@@ -33,7 +41,7 @@ ok(open(F, '>', $lock), "create bogus ${LockDir}visitors");
 my $ts = time - 120;
 utime($ts, $ts, $lock); # change mtime of the lockfile
 
-# Getting a time will now time out because no visitor lock can ge aquired.
+# Getting a time will now time out because no visitor lock can be acquired.
 $ts = time;
 get_page('fail-to-get-lock');
 

t/test.pl

@@ -330,26 +330,16 @@ sub write_config_file {
 }
 
 sub write_modified_wiki {
-  my $preamble = <<EOT;
+  my $preamble = <<'EOT';
 
 BEGIN {
-  my \$delta = 0;
-
-  *CORE::GLOBAL::sleep = sub {
-    \$delta += shift;
-    my \$ts = time + \$delta;
-    utime(\$ts, \$ts, "$DataDir/ts")
-  };
-
-  sub newtime {
-    return time + \$delta;
-  };
-
-  *CORE::GLOBAL::time = \&newtime;
+  sub updateFakeTime { utime($_[0], $_[0], "$DataDir/ts") }
+  *CORE::GLOBAL::sleep = sub { updateFakeTime((stat("$DataDir/ts"))[9] + $_[0]) };
+  *CORE::GLOBAL::time  = sub { (stat("$DataDir/ts"))[9] };
 }
 
 EOT
-     
+
   WriteStringToFile("$DataDir/test-wiki.pl", $preamble . ReadFileOrDie('wiki.pl'));
   WriteStringToFile("$DataDir/ts", '');
 }