NewNighlytTest: Fix timestamp format to actually make sense (it was missing the hour).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86229 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/NewNightlyTest.pl b/utils/NewNightlyTest.pl
index f74711a..62054ed 100755
--- a/utils/NewNightlyTest.pl
+++ b/utils/NewNightlyTest.pl
@@ -122,8 +122,9 @@
 # Calculate the date prefix...
 #
 ##############################################################
+use POSIX;
 @TIME = localtime;
-my $DATE = sprintf "%4d-%02d-%02d_%02d-%02d", $TIME[5]+1900, $TIME[4]+1, $TIME[3], $TIME[1], $TIME[0];
+my $DATE = strftime("%Y-%m-%d_%H-%M-%S", localtime());
 
 ##############################################################
 #