masihdindar what's your computer timezone? The hour:minute shown in the browser is according to the browser's current time, so there shouldn't be any error there. But maybe your browser is/isn't in daylight saving mode while your operating system is? I'm not sure how browser and operating system can differ though.
Often when we see 2-hour errors it has something to do with UTC and Central European time (UTC+2). Make sure the webserver and database servers are running the same timezone, ideally run everything as UTC if you can.
The time from the server is always converted from the server timezone to UTC before being sent to the browser, where native javascript functions are used to display the time in the client's browser timezone.
EDIT: I was waiting to post to verify, the time looks good on discuss.flarum.org for me, it shows 7:05 PM as my post creation, which matches with the 19:05 time on my computer clock (CET)
