The timestamps on messenger are wrong, off by hours.

No help from me. I notice that many of my emails (through yahoo) are also off by a similar amount.

So much of the net operates from varying time zones, it doesn't surprise me.

Check the timezone settings on your apps.

Timezones on my phone are all correct and set to automatic. Thing is that on my phone so far the timestamps are correct. The problem is with messenger on firefox on my pc, where time also is correct.

I'd like to mention how surprised I am that there is no way to ask someone from fb itself to help me with this. Also in reddit, under facebook category whenever I start a thread with any issue I face. they always remove it with a generic explanation (sort title or something like this). And I am always polite and obviously I know how to start a thread properly. They don't care, right?

From everything I've heard, you are right.

Why is it important?

If you mean why is it important to have correct timestamps, it is only because I would like to know around what time a message has been sent to me. Sometimes it is essential.