--- os/log.c.old	2010-01-23 02:08:06.000000000 +0100
+++ os/log.c	2010-01-23 03:34:45.000000000 +0100
@@ -108,6 +108,8 @@
 #endif
 
 static FILE *logFile = NULL;
+static Bool logTimestamp = TRUE;
+static Bool logFileTimestamp = TRUE;
 static Bool logFlush = FALSE;
 static Bool logSync = FALSE;
 static int logVerbosity = DEFAULT_LOG_VERBOSITY;
@@ -257,7 +259,12 @@
 LogVWrite(int verb, const char *f, va_list args)
 {
     static char tmpBuffer[1024];
+    static char timestamp[21];
     int len = 0;
+    size_t timestamp_len = 0;
+    Bool hasNewline = FALSE;
+    time_t t;
+    struct tm *tm;
 
     /*
      * Since a va_list can only be processed once, write the string to a
@@ -267,12 +274,34 @@
     if (verb < 0 || logFileVerbosity >= verb || logVerbosity >= verb) {
 	vsnprintf(tmpBuffer, sizeof(tmpBuffer), f, args);
 	len = strlen(tmpBuffer);
+	if (len == 0)
+	    return;
+    } else {
+	return;
     }
-    if ((verb < 0 || logVerbosity >= verb) && len > 0)
+    if (logTimestamp || logFileTimestamp) {
+	t = time(NULL);
+	if (t != (time_t)-1)
+	    tm = localtime(&t);
+	else
+	    tm = NULL;
+	if (tm != NULL)
+	    timestamp_len = strftime(timestamp, sizeof(timestamp), "%F %T ", tm);
+    }
+    hasNewline = (strchr(tmpBuffer, '\n') != NULL);
+    if ((verb < 0 || logVerbosity >= verb)) {
+	if (logTimestamp && timestamp_len)
+	    fwrite(timestamp, timestamp_len, 1, stderr);
+	logTimestamp = hasNewline;
 	fwrite(tmpBuffer, len, 1, stderr);
-    if ((verb < 0 || logFileVerbosity >= verb) && len > 0) {
+    }
+    if ((verb < 0 || logFileVerbosity >= verb)) {
 	if (logFile) {
+	    if (logFileTimestamp && timestamp_len)
+		fwrite(timestamp, timestamp_len, 1, logFile);
+	    logFileTimestamp = hasNewline;
 	    fwrite(tmpBuffer, len, 1, logFile);
+
 	    if (logFlush) {
 		fflush(logFile);
 #ifndef WIN32
@@ -286,8 +315,8 @@
 	     * xalloc() and friends can't be used.
 	     */
 	    if (len > bufferUnused) {
-		bufferSize += 1024;
-		bufferUnused += 1024;
+		bufferSize += 1024 + timestamp_len;
+		bufferUnused += 1024 + timestamp_len;
 		if (saveBuffer)
 		    saveBuffer = realloc(saveBuffer, bufferSize);
 		else
@@ -295,7 +324,9 @@
 		if (!saveBuffer)
 		    FatalError("realloc() failed while saving log messages\n");
 	    }
-	    bufferUnused -= len;
+	    bufferUnused -= (timestamp_len + len);
+	    memcpy(saveBuffer + bufferPos, timestamp, timestamp_len);
+	    bufferPos += timestamp_len;
 	    memcpy(saveBuffer + bufferPos, tmpBuffer, len);
 	    bufferPos += len;
 	}