timezone error

i use this with Worona plugin and get this error:

<b>Fatal error</b>: Uncaught exception ‘Exception’ with message ‘DateTimeZone::__construct(): Unknown or bad timezone (Etc/GMT+3.5)’ in /home/mashinba/public_html/wp-content/plugins/worona/json-rest-api/plugin.php:672

Stack trace:
#0 /home/mashinba/public_html/wp-content/plugins/worona/json-rest-api/plugin.php(672): DateTimeZone->__construct(‘Etc/GMT+3.5’)

#1 /home/mashinba/public_html/wp-content/plugins/worona/json-rest-api/lib/class-wp-json-posts.php(584): json_get_timezone()

#2 /home/mashinba/public_html/wp-content/plugins/worona/json-rest-api/lib/class-wp-json-posts.php(188): WP_JSON_Posts->prepare_post(Array, ‘view’)

#3 [internal function]: WP_JSON_Posts->get_posts(Array, ‘view’, ‘post’, 1)

#4 /home/mashinba/public_html/wp-content/plugins/worona/json-rest-api/lib/class-wp-json-server.php(444): call_user_func_array(Array, Array)

#5 /home/mashinba/public_html/wp-content/plugins/worona/json-rest-api/lib/class-wp-json-server.php(248): WP_JSON_Server->dispatch()

#6 /home/mashinba/public_html/wp-content/plugins/worona/json-rest-a in <b>/home/mashinba/public_html/wp-content/plugins/worona/json-rest-api/plugin.php</b> on line <b>672</b>

please check this and solve problem

https://ww.wp.xz.cn/plugins/json-rest-api/