diff --git a/HISTORY b/HISTORY
index f9d57fc6..9f9d9806 100644
--- a/HISTORY
+++ b/HISTORY
@@ -19,6 +19,8 @@ SnapRAID HISTORY
  * In "fix", if a previous fixing attempt was made resulting in a
    .unrecoverable file, uses this file as starting point for the
    new attempt.
+ * In the log file name allow the use of the '>>', %D, %T modifiers
+   to select append mode, and to insert the date and time in the name.
  * New source code organization. The RAID engine is now
    an external component usable also in other projects.
 
diff --git a/Makefile.am b/Makefile.am
index f138604b..c6b3a18a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -101,7 +101,7 @@ man_MANS = snapraid.1
 clean-local:
 	rm -f valgrind.log callgrind.log cachegrind.log
 	rm -rf test
-	rm -f test.log output.log
+	rm -f test*.log output.log
 	rm -f *.gcda *.gcno *.gcov
 	rm -rf cov
 	rm -f lcov.info
@@ -144,12 +144,16 @@ check-local:
 	$(TESTENV) ./snapraid$(EXEEXT) --test-skip-device -c $(CONF) status
 	echo --- Run the speed test
 	$(TESTENV) ./snapraid$(EXEEXT) --test-skip-device -T
-	echo --- As empty, sync and check forcing murmur3
+	echo --- Some commands with empty array
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -v -c $(CONF) diff
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -v -c $(CONF) dup
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -v -c $(CONF) list > output.log
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) --test-force-murmur3 sync
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) status
+	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) status -l ">&1"
+	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) status -l ">&2"
+	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) status -l ">>test.log"
+	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) status -l test-%D-%T.log
 if HAVE_SYMLINK
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(PAR1) pool
 endif
diff --git a/snapraid.1 b/snapraid.1
index 33fc2758..3014a640 100644
--- a/snapraid.1
+++ b/snapraid.1
@@ -820,6 +820,10 @@ and you\(cqll get only a summary at the end of the operations.
 When checking and fixing this allows to keep separated
 the possible huge list of errors from the human readable
 output.
+If the specified FILE path start with \(cq>>\(cq the file is opened
+in append mode. Inside the path, occurrences of %D and %T are
+replaced with the date and time in the format YYYYMMDD and
+HHMMSS.
 .TP
 .B \-s, \-\-start BLKSTART
 Starts the processing from the specified
diff --git a/snapraid.c b/snapraid.c
index 724dfecb..92dd008c 100644
--- a/snapraid.c
+++ b/snapraid.c
@@ -86,6 +86,105 @@ void memory(void)
 	printf("Using %u MiB of memory.\n", (unsigned)(malloc_counter() / 1024 / 1024));
 }
 
+void log_open(const char* log)
+{
+	char path[PATH_MAX];
+	const char* mode;
+	char text_T[32];
+	char text_D[32];
+	time_t t;
+	struct tm* tm;
+
+	/* if no log file is specified, don't output */
+	if (log == 0) {
+#ifdef _WIN32
+		log = "NUL";
+#else
+		log = "/dev/null";
+#endif
+	}
+
+	t = time(0);
+	tm = localtime(&t);
+	if (tm) {
+		strftime(text_T, sizeof(text_T), "%H%M%S", tm);
+		strftime(text_D, sizeof(text_T), "%Y%m%d", tm);
+	} else {
+		strcpy(text_T, "invalid");
+		strcpy(text_D, "invalid");
+	}
+
+	/* file mode */
+	mode = "wt";
+	if (*log == '>') {
+		++log;
+
+		if (*log == '>') {
+			mode = "at";
+			++log;
+		}
+
+		if (log[0] == '&' && log[1] == '1') {
+			stdlog = stdout;
+			return;
+		}
+
+		if (log[0] == '&' && log[1] == '2') {
+			stdlog = stderr;
+			return;
+		}
+	}
+
+	/* process the path */
+	for(*path=0;*log!=0;) {
+		switch (*log) {
+		case '%' :
+			++log;
+			switch (*log) {
+			case '%' :
+				pathcatc(path, sizeof(path), '%');
+				break;
+			case 'T' :
+				pathcat(path, sizeof(path), text_T);
+				break;
+			case 'D' :
+				pathcat(path, sizeof(path), text_D);
+				break;
+			default:
+				/* LCOV_EXCL_START */
+				fprintf(stderr, "Invalid type specifier '%c' in the log file.\n", *log);
+				exit(EXIT_FAILURE);
+				/* LCOV_EXCL_STOP */
+			}
+			break;
+		default:
+			pathcatc(path, sizeof(path), *log);
+			break;
+		}
+		++log;
+	}
+
+	stdlog = fopen(path, mode);
+	if (!stdlog) {
+		/* LCOV_EXCL_START */
+		fprintf(stderr, "Error opening the log file '%s'. %s.\n", path, strerror(errno));
+		exit(EXIT_FAILURE);
+		/* LCOV_EXCL_STOP */
+	}
+}
+
+void log_close(const char* log)
+{
+	if (stdlog != stdout && stdlog != stderr) {
+		if (fclose(stdlog) != 0) {
+			/* LCOV_EXCL_START */
+			fprintf(stderr, "Error closing the log file '%s'. %s.\n", log, strerror(errno));
+			exit(EXIT_FAILURE);
+			/* LCOV_EXCL_STOP */
+		}
+	}
+}
+
 #define OPT_TEST_SKIP_SELF 256
 #define OPT_TEST_KILL_AFTER_SYNC 257
 #define OPT_TEST_EXPECT_UNRECOVERABLE 258
@@ -584,27 +683,8 @@ int main(int argc, char* argv[])
 		}
 	}
 
-	/* if no log file is specified, don't output */
-	if (log == 0) {
-#ifdef _WIN32
-		log = "NUL";
-#else
-		log = "/dev/null";
-#endif
-	}
-	if (strcmp(log, "1") == 0) {
-		stdlog = stdout;
-	} else if (strcmp(log, "2") == 0) {
-		stdlog = stderr;
-	} else {
-		stdlog = fopen(log, "wt");
-		if (!stdlog) {
-			/* LCOV_EXCL_START */
-			fprintf(stderr, "Error opening the log file '%s'. %s.\n", log, strerror(errno));
-			exit(EXIT_FAILURE);
-			/* LCOV_EXCL_STOP */
-		}
-	}
+	/* open the log file */
+	log_open(log);
 
 	if (!opt.skip_self)
 		selftest();
@@ -786,14 +866,7 @@ int main(int argc, char* argv[])
 	}
 
 	/* close log file */
-	if (stdlog != stdout && stdlog != stderr) {
-		if (fclose(stdlog) != 0) {
-			/* LCOV_EXCL_START */
-			fprintf(stderr, "Error closing the log file '%s'. %s.\n", log, strerror(errno));
-			exit(EXIT_FAILURE);
-			/* LCOV_EXCL_STOP */
-		}
-	}
+	log_close(log);
 
 #if HAVE_LOCKFILE
 	if (!opt.skip_lock) {
diff --git a/snapraid.d b/snapraid.d
index f90bff55..59a7fd60 100644
--- a/snapraid.d
+++ b/snapraid.d
@@ -586,6 +586,10 @@ Options
 		When checking and fixing this allows to keep separated
 		the possible huge list of errors from the human readable
 		output.
+		If the specified path starts with '>>' the file is opened
+		in append mode. Occurrences of %D and %T in the name are
+		replaced with the date and time in the format YYYYMMDD and
+		HHMMSS.
 
 	-s, --start BLKSTART
 		Starts the processing from the specified
diff --git a/snapraid.txt b/snapraid.txt
index 31dc3e0a..e109434e 100644
--- a/snapraid.txt
+++ b/snapraid.txt
@@ -631,6 +631,10 @@ SnapRAID provides the following options:
         When checking and fixing this allows to keep separated
         the possible huge list of errors from the human readable
         output.
+        If the specified path starts with '>>' the file is opened
+        in append mode. Occurrences of %D and %T in the name are
+        replaced with the date and time in the format YYYYMMDD and
+        HHMMSS.
 
     -s, --start BLKSTART
         Starts the processing from the specified
diff --git a/state.c b/state.c
index e0dd2013..5587310a 100644
--- a/state.c
+++ b/state.c
@@ -347,6 +347,8 @@ void state_config(struct snapraid_state* state, const char* path, const char* co
 	unsigned line;
 	tommy_node* i;
 	unsigned l;
+	time_t t;
+	struct tm* tm;
 
 	/* copy the options */
 	state->opt = *opt;
@@ -357,7 +359,16 @@ void state_config(struct snapraid_state* state, const char* path, const char* co
 	
 	state->command = command;
 
+	t = time(0);
+	tm = localtime(&t);
+
 	fprintf(stdlog, "version:%s\n", PACKAGE_VERSION);
+	fprintf(stdlog, "unixtime:%"PRIi64"\n", (int64_t)t);
+	if (tm) {
+		char datetime[64];
+		strftime(datetime, sizeof(datetime), "%F %T", tm);
+		fprintf(stdlog, "time:%s\n", datetime);
+	}
 	fprintf(stdlog, "conf:%s\n", path);
 	fflush(stdlog);
 
diff --git a/util.c b/util.c
index 692abb19..e48ff2d7 100644
--- a/util.c
+++ b/util.c
@@ -1267,6 +1267,21 @@ void pathcat(char* dst, size_t size, const char* src)
 	memcpy(dst + dst_len, src, src_len + 1);
 }
 
+void pathcatc(char* dst, size_t size, char c)
+{
+	size_t dst_len = strlen(dst);
+
+	if (dst_len + 2 > size) {
+		/* LCOV_EXCL_START */
+		fprintf(stderr, "Path too long\n");
+		exit(EXIT_FAILURE);
+		/* LCOV_EXCL_STOP */
+	}
+
+	dst[dst_len] = c;
+	dst[dst_len + 1] = 0;
+}
+
 void pathimport(char* dst, size_t size, const char* src)
 {
 	pathcpy(dst, size, src);
diff --git a/util.h b/util.h
index e528ec63..a6ed2e13 100644
--- a/util.h
+++ b/util.h
@@ -403,6 +403,12 @@ void pathcpy(char* dst, size_t size, const char* src);
  */
 void pathcat(char* dst, size_t size, const char* src);
 
+/**
+ * Concatenates a path limiting the size.
+ * Aborts if too long.
+ */
+void pathcatc(char* dst, size_t size, char c);
+
 /**
  * Imports a path limiting the size.
  * In Windows all the backslash are converted to the C standard of forward slash.