diff --git a/ext/hook.c b/ext/hook.c
index 08f2d79..b1c4166 100644
--- a/ext/hook.c
+++ b/ext/hook.c
@@ -183,6 +183,7 @@ static inline void apply_interval(timelib_time **time, timelib_rel_time *interva
 		zend_string *format, *_datetime; \
 		zval *_timezone_object; \
 		format_flags_t flags; \
+		timelib_time *orig, *shifted; \
 		\
 		CALL_ORIGINAL_FUNCTION(name); \
 		if (!return_value || Z_TYPE_P(return_value) == IS_FALSE || !Z_PHPDATE_P(return_value)->time) { \
@@ -198,26 +199,37 @@ static inline void apply_interval(timelib_time **time, timelib_rel_time *interva
 		\
 		parse_format(ZSTR_VAL(format), &flags); \
 		\
-		timelib_time temp; \
-		timelib_rel_time interval; \
-		get_shift_interval(&interval); \
-		memcpy(&temp, Z_PHPDATE_P(return_value)->time, sizeof(timelib_time)); \
+		/* backup original method result */ \
+		orig = timelib_time_clone(Z_PHPDATE_P(return_value)->time); \
+		shifted = get_shifted_timelib_time(orig->tz_info); \
+		\
+		/* overwrite current shifted datetime */ \
+		Z_PHPDATE_P(return_value)->time->y = shifted->y; \
+		Z_PHPDATE_P(return_value)->time->m = shifted->m; \
+		Z_PHPDATE_P(return_value)->time->d = shifted->d; \
+		Z_PHPDATE_P(return_value)->time->h = shifted->h; \
+		Z_PHPDATE_P(return_value)->time->i = shifted->i; \
+		Z_PHPDATE_P(return_value)->time->s = shifted->s; \
+		Z_PHPDATE_P(return_value)->time->us = shifted->us; \
 		\
-		apply_interval(&Z_PHPDATE_P(return_value)->time, &interval); \
+		/* restore original method result if required */ \
 		if (flags.h || flags.i || flags.s || flags.us) { \
 			Z_PHPDATE_P(return_value)->time->h = 0; \
 			Z_PHPDATE_P(return_value)->time->i = 0; \
 			Z_PHPDATE_P(return_value)->time->s = 0; \
 			Z_PHPDATE_P(return_value)->time->us = 0; \
 		} \
-		if (flags.y) { Z_PHPDATE_P(return_value)->time->y = temp.y; } \
-		if (flags.m) { Z_PHPDATE_P(return_value)->time->m = temp.m; } \
-		if (flags.d) { Z_PHPDATE_P(return_value)->time->d = temp.d; } \
-		if (flags.h) { Z_PHPDATE_P(return_value)->time->h = temp.h; } \
-		if (flags.i) { Z_PHPDATE_P(return_value)->time->i = temp.i; } \
-		if (flags.s) { Z_PHPDATE_P(return_value)->time->s = temp.s; } \
-		if (flags.us) { Z_PHPDATE_P(return_value)->time->us = temp.us; } \
+		if (flags.y) { Z_PHPDATE_P(return_value)->time->y = orig->y; } \
+		if (flags.m) { Z_PHPDATE_P(return_value)->time->m = orig->m; } \
+		if (flags.d) { Z_PHPDATE_P(return_value)->time->d = orig->d; } \
+		if (flags.h) { Z_PHPDATE_P(return_value)->time->h = orig->h; } \
+		if (flags.i) { Z_PHPDATE_P(return_value)->time->i = orig->i; } \
+		if (flags.s) { Z_PHPDATE_P(return_value)->time->s = orig->s; } \
+		if (flags.us) { Z_PHPDATE_P(return_value)->time->us = orig->us; } \
 		\
+		/* release shifted time */ \
+		timelib_time_dtor(orig); \
+		timelib_time_dtor(shifted); \
 		timelib_update_ts(Z_PHPDATE_P(return_value)->time, NULL); \
 	}
 
@@ -303,18 +315,23 @@ static inline bool is_fixed_time_str(zend_string *datetime, zval *timezone)
 	return is_fixed_time_str;
 }
 
-static inline timelib_time *get_current_timelib_time()
+static inline timelib_time *get_current_timelib_time(timelib_tzinfo *tzi)
 {
 	timelib_time *t = timelib_time_ctor();
 
-	timelib_unixtime2gmt(t, php_time());
+	if (tzi != NULL) {
+		timelib_set_timezone(t, tzi);
+		timelib_unixtime2local(t, (timelib_sll) php_time());
+	} else {
+		timelib_unixtime2gmt(t, php_time());
+	}
 
 	return t;
 }
 
-static inline timelib_time *get_shifted_timelib_time()
+static inline timelib_time *get_shifted_timelib_time(timelib_tzinfo *tzi)
 {
-	timelib_time *t = get_current_timelib_time();
+	timelib_time *t = get_current_timelib_time(tzi);
 	timelib_rel_time interval;
 
 	get_shift_interval(&interval);
@@ -323,10 +340,10 @@ static inline timelib_time *get_shifted_timelib_time()
 	return t;
 }
 
-static inline time_t get_shifted_time()
+static inline time_t get_shifted_time(timelib_tzinfo *tzi)
 {
 	time_t timestamp;
-	timelib_time *t = get_shifted_timelib_time();
+	timelib_time *t = get_shifted_timelib_time(tzi);
 
 	timestamp = t->sse;
 
@@ -344,7 +361,7 @@ static inline bool pdo_time_apply(pdo_dbh_t *dbh)
 		return false;
 	}
 
-	zend_sprintf(buf, "SET @@session.timestamp = %ld;", get_shifted_time());
+	zend_sprintf(buf, "SET @@session.timestamp = %ld;", get_shifted_time(NULL));
 	sql = zend_string_init_fast(buf, strlen(buf));
 	COLOPL_TS_G(pdo_mysql_orig_methods)->doer(dbh, sql);
 	zend_string_release(sql);
@@ -469,7 +486,7 @@ static inline void date_common(INTERNAL_FUNCTION_PARAMETERS, int localtime)
 	ZEND_PARSE_PARAMETERS_END();
 
 	if (ts_is_null) {
-		ts = get_shifted_time();
+		ts = get_shifted_time(NULL);
 	}
 
 	RETVAL_STR(php_format_date(ZSTR_VAL(format), ZSTR_LEN(format), ts, localtime));
@@ -518,7 +535,7 @@ static void hook_time(INTERNAL_FUNCTION_PARAMETERS)
 	CHECK_STATE(time);
 
 	CALL_ORIGINAL_FUNCTION(time);
-	RETURN_LONG(get_shifted_time());
+	RETURN_LONG(get_shifted_time(NULL));
 }
 
 static void hook_mktime(INTERNAL_FUNCTION_PARAMETERS)
@@ -592,7 +609,7 @@ static void hook_idate(INTERNAL_FUNCTION_PARAMETERS)
 	ZEND_PARSE_PARAMETERS_END();
 
 	if (ts_is_null) {
-		ts = get_shifted_time();
+		ts = get_shifted_time(NULL);
 	}
 
 	RETURN_LONG(php_idate(ZSTR_VAL(format)[0], ts, 0));
@@ -616,7 +633,7 @@ static void hook_getdate(INTERNAL_FUNCTION_PARAMETERS)
 
 	/* Call original function with timestamp params. */
 	zval params[1];
-	ZVAL_LONG(&params[0], get_shifted_time());
+	ZVAL_LONG(&params[0], get_shifted_time(NULL));
 	CALL_ORIGINAL_FUNCTION_WITH_PARAMS(getdate, params, 1);
 }
 
@@ -635,7 +652,7 @@ static void hook_localtime(INTERNAL_FUNCTION_PARAMETERS)
 
 	/* Call original function with params. */
 	zval params[2];
-	ZVAL_LONG(&params[0], get_shifted_time());
+	ZVAL_LONG(&params[0], get_shifted_time(NULL));
 	ZVAL_BOOL(&params[1], associative);
 	CALL_ORIGINAL_FUNCTION_WITH_PARAMS(localtime, params, 2);
 }
@@ -658,7 +675,7 @@ static void hook_strtotime(INTERNAL_FUNCTION_PARAMETERS)
 	times_lower = zend_string_tolower(times);
 	if (strncmp(ZSTR_VAL(times_lower), "now", 3) == 0) {
 		zend_string_release(times_lower);
-		RETURN_LONG((zend_long) get_shifted_time());
+		RETURN_LONG((zend_long) get_shifted_time(NULL));
 	}
 	zend_string_release(times_lower);
 
@@ -671,7 +688,7 @@ static void hook_strtotime(INTERNAL_FUNCTION_PARAMETERS)
 	zval *params = NULL;
 	uint32_t param_count = 0;
 	zend_parse_parameters(ZEND_NUM_ARGS(), "+", &params, &param_count);
-	ZVAL_LONG(&params[1], get_shifted_time());
+	ZVAL_LONG(&params[1], get_shifted_time(NULL));
 	CALL_ORIGINAL_FUNCTION_WITH_PARAMS(strtotime, params, param_count);
 
 	/* Apply interval. */
diff --git a/ext/tests/gh7.phpt b/ext/tests/gh7.phpt
index df60ae6..6f52858 100644
--- a/ext/tests/gh7.phpt
+++ b/ext/tests/gh7.phpt
@@ -8,15 +8,11 @@ colopl_timeshifter
 $first = date_create_from_format('Ymd', '19941026');
 \Colopl\ColoplTimeShifter\register_hook(new DateInterval('PT1H'));
 $second = date_create_from_format('Ymd', '19941026');
-/* Sometimes delay */
-if ($first->diff($second)->format('%h%i%s') !== '100' && $first->diff($second)->format('%h%i%s') !== '05959') {
-    die('fail: ' . $first->diff($second)->format('%h%i%s'));
-}
 echo $first->diff($second)->format('%y-%m-%d %h:%i:%s.%F'), \PHP_EOL;
 \Colopl\ColoplTimeShifter\unregister_hook();
 
 $first = date_create_from_format('i', '30');
-\Colopl\ColoplTimeShifter\register_hook(new DateInterval('P1MT30S'));
+\Colopl\ColoplTimeShifter\register_hook(new DateInterval('P1M'));
 $second = date_create_from_format('i', '30');
 echo $first->diff($second)->format('%y-%m-%d %h:%i:%s.%F'), \PHP_EOL;
 \Colopl\ColoplTimeShifter\unregister_hook();
diff --git a/ext/tests/gh9.phpt b/ext/tests/gh9.phpt
new file mode 100644
index 0000000..6fa399b
--- /dev/null
+++ b/ext/tests/gh9.phpt
@@ -0,0 +1,35 @@
+--TEST--
+Check GitHub PR - #9 (wrong createFromFormat of start of month)
+--EXTENSIONS--
+colopl_timeshifter
+--SKIPIF--
+<?php
+if (posix_getuid() !== 0) die('skip require root');
+if (! is_string(($result = shell_exec('date -s "2024-09-01"')))) die ('skip cannot set current date');
+try {
+    $dt = new \DateTimeImmutable($result);
+    if (!($dt instanceof \DateTimeImmutable)) {
+        throw new Exception("construction failed: {$result}");
+    }
+} catch (\Exception $e) {
+    die("skip {$e->getmessage()}");
+}
+if ($dt->format('d') !== '01') die('skip not start of month');
+?>
+--FILE--
+<?php
+
+$interval = new DateInterval('P1D');
+
+$first = new \DateTime();
+echo $first->format('Y-m-d H:i:s.u'), \PHP_EOL;
+\Colopl\ColoplTimeShifter\register_hook($interval);
+echo (new \DateTime())->format('Y-m-d H:i:s.u'), \PHP_EOL;
+$second = date_create_from_format('d', '10');
+echo $second->format('Y-m-d H:i:s.u'), \PHP_EOL;
+
+?>
+--EXPECTF--
+2024-09-01 %d:%d:%d.%d
+2024-08-31 %d:%d:%d.%d
+2024-08-10 00:00:%d.000000
diff --git a/ext/tests/variables/request_time_float.phpt b/ext/tests/variables/request_time_float.phpt
index 3cc5c74..04e599c 100644
--- a/ext/tests/variables/request_time_float.phpt
+++ b/ext/tests/variables/request_time_float.phpt
@@ -20,10 +20,6 @@ if ($before == $after || $interval->y <= 0 || $interval->invert !== 0) {
     die('failed');
 }
 
-if ($before->format('u') !== $after->format('u')) {
-    die('failed');
-}
-
 die('success');
 
 ?>