diff -up lftp-4.2.1/src/Http.cc.date_fmt lftp-4.2.1/src/Http.cc

--- lftp-4.2.1/src/Http.cc.date_fmt	2011-03-25 15:35:42.000000000 +0100

+++ lftp-4.2.1/src/Http.cc	2011-03-30 14:40:54.170096624 +0200

@@ -29,6 +29,7 @@

 #include <errno.h>

 #include <stdarg.h>

 #include <time.h>

+#include <limits.h>

 #include <fnmatch.h>

 #include <locale.h>

 #include <assert.h>

@@ -565,15 +566,10 @@ void Http::SendRequest(const char *conne

 		     (long long)((limit==FILE_END || limit>entity_size ? entity_size : limit)-1),

 		     (long long)entity_size);

       }

-      if(entity_date!=NO_DATE)

+      if(entity_date!=NO_DATE && entity_date>0L && entity_date

       {

-	 static const char weekday_names[][4]={

-	    "Sun","Mon","Tue","Wed","Thu","Fri","Sat"

-	 };

-	 const struct tm *t=gmtime(&entity_date);

-	 const char *d=xstring::format("%s, %2d %s %04d %02d:%02d:%02d GMT",

-	    weekday_names[t->tm_wday],t->tm_mday,month_names[t->tm_mon],

-	    t->tm_year+1900,t->tm_hour,t->tm_min,t->tm_sec);

+         char d[256];

+         strftime(d, sizeof(d), "%a, %d %b %H:%M:%S %Y GMT", gmtime(&entity_date));

 	 Send("Last-Modified: %s\r\n",d);

       }

       break;