Write down the logic behind the localtime vs gmtime date ranges.

2 files changed, 4 insertions, 1 deletions

diff --git a/lib/Time/gmtime.t b/lib/Time/gmtime.t
index 0e3855c8db..383eeda73a 100644
--- a/lib/Time/gmtime.t
+++ b/lib/Time/gmtime.t
@@ -11,7 +11,8 @@ BEGIN { plan tests => 37; }
 
 BEGIN { use_ok Time::gmtime; }
 
-for my $time (0, 2**31-1, 2**33, time) {
+# Perl has its own gmtime() so it's safe to do negative times.
+for my $time (-2**33, -2**31-1, 0, 2**31-1, 2**33, time) {
     my $gmtime = gmtime $time;          # This is the OO gmtime.
     my @gmtime = CORE::gmtime $time;    # This is the gmtime function
 
diff --git a/lib/Time/localtime.t b/lib/Time/localtime.t
index 5d935e76b8..10df765fc3 100644
--- a/lib/Time/localtime.t
+++ b/lib/Time/localtime.t
@@ -25,6 +25,8 @@ BEGIN { plan tests => 37; }
 
 BEGIN { use_ok Time::localtime; }
 
+# Since Perl's localtime() still uses the system localtime, don't try
+# to do negative times.  The system might not support it.
 for my $time (0, 2**31-1, 2**33, time) {
     my $localtime = localtime $time;          # This is the OO localtime.
     my @localtime = CORE::localtime $time;    # This is the localtime function