Patch 1.0.3

Somehow the setTimezone update was not

`setTimezone()`` as well is chainable.
```php
$t = ts('previous monday 23:00', true)
   	->setTimezone('America/Los_Angeles');
```

Author: PandaHugMonster

README.md

@@ -58,9 +58,9 @@ so documentation will come after that in the very nearest time. My apologies.
 
 Minimal PHP version: **8.0**
 
-Current framework version: **1.0.0**
+Current framework version: **1.0.3**
 ```shell
-composer require spaf/simputils "~1"
+composer require spaf/simputils "^1"
 ```
 
 Keep in mind that the library development suppose to follow the semantic versioning,

src/PHP.php

@@ -106,7 +106,7 @@ public static function frameworkDir() {
 	 */
 	public static function simpUtilsVersion(): Version|string {
 		$class = static::redef(Version::class);
-		return new $class('1.0.2', 'SimpUtils');
+		return new $class('1.0.3', 'SimpUtils');
 	}
 
 	/**

src/models/DateTime.php

@@ -163,6 +163,9 @@ public function setTimezone($timezone): static {
 		if (is_string($timezone)) {
 			$timezone = new $class_tz($timezone);
 		}
+		if (empty($timezone)) {
+			$timezone = 'UTC';
+		}
 		return parent::setTimezone($timezone);
 	}