One of the new things in PHP 5.1 is the $_SERVER['REQUEST_TIME'] variable that gets set to the request time.  When running under Apache this comes directly from the time syscall Apache makes for every request, so by using this you can actually eliminate any time-related syscalls at the PHP level and still do time stuff in a PHP script.  But yes, it looks like there are a few things that can be cleaned up here.

sniper: the latest cvs exhibits the same problem.

rasmus: $_SERVER["REQUEST_TIME"] is a nice addition, but in my case I just want to convert timestamps stored in a db to a readable format, hence no need for the current time at all ...

the following patch address the unneeded call to time(NULL), strace confirms it, but the performance is still not on par with 5.0

--- php5-200510011430/ext/date/php_date.c.orig  2005-10-01 18:16:55.000000000 +0200
+++ php5-200510011430/ext/date/php_date.c       2005-10-01 18:17:48.000000000 +0200
@@ -479,11 +479,23 @@
 {
        char *format;
        int   format_len;
-       time_t  ts = time(NULL);
+       time_t  ts;
        char           *string;
 
-       if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|l", &format, &format_len, &ts) == FAILURE) {
-               RETURN_FALSE;
+       switch (ZEND_NUM_ARGS()) {
+       case 2:
+               if (zend_parse_parameters(2 TSRMLS_CC, "sl", &format, &format_len, &ts) == FAILURE) {
+                       RETURN_FALSE;
+               }
+               break;
+       case 1:
+               if (zend_parse_parameters(1 TSRMLS_CC, "s", &format, &format_len) == FAILURE) {
+                       RETURN_FALSE;
+               }
+               ts = time(NULL);
+               break;
+       default:
+               WRONG_PARAM_COUNT;
        }
 
        string = php_format_date(format, format_len, ts, localtime TSRMLS_CC);

Right, the timezone lookup is currently slower.  There needs to be a cache layer in front of it.  It will come eventually.  We know about it.

So that I can't forget this.

This bug has been fixed in CVS.

Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
 
Thank you for the report, and for helping us make PHP better.

The syscall has been eliminated and the tzcache is in place now in CVS. It is still slower, but not as bad as it was. Also, things improve greatly if you use the date.timezone setting in php.ini to select the timezone (in the format "America/New_York" f.e.) that you are actually in.