This topic is entirely based upon region. If you dislike it or feel im doing it wrong, leave now. It is slightly annoying to the western world and steriotypes them a little, but for good reason. You have been warned =3.

So I began thinking this question around 4 months ago and im sure server owners around the globe have thought this...
When do I bump my PMC server?

Well I currently run a server at: www.planetminecraft.com/server/creative-162-server-freebuild-no-greifing-great-staff-no-plot-restrictions/ and trust me, some of you server owners have seen nothing greifing wise. We run a creative server with no restrictions, no set plots and the only thing protecting it is good old classic admins, coreprotect and backups.

So what does this mean?
Well we constatly get bombarded with greifers... But I found out something intresting in these 4 months. I started recording a table of the people and percentage of people who greifed at differen't timezones. I found that on average... Get this. 78% of the western world UTC (-5,-6,-7) etc.. greifed when they joined a new. We have an i.p finder on our server that indicated the country and this is what we found.

and your point is?
Well I tested at general GMT +0 time, as I myself am english. And I found that from europe and genuinly I was shocked by this, after we recorded the results, only 12%(rounded) of new players had come intentionally to greif. I had to check it about 4 times with the different timezones and again the results where nearly exactly the same.
I then went into different timezones, australian, etc... I didn't record australia's results in depth but I remember it being considerably lower than the western world, again.

I also began to find habbits in days I bumped my thread.
Fridays - Hopeless, nearly everyone seems to greif.
Saturdays/sundays - A mixture
Monday - thursdays - Considerably less greifers.

I seem to have become besotted with this question, unfortunatly, I did make these statistics in a google docs sheet that seemed to be destroyed by a fellow member... :(. So if you don't agree with me I can understand why.

So I finally came to my conclusion...
If you don't want as many greifers, certainly in my slightly bias case of only testing one server.
Go for GMT +0 timezone on a monday - thursday.

Thanks for reading, please any comments or edits you want me to make, suggest below.