Problem: WordPress is showing the wrong date and time on published posts and in the “Posts” list inside wp-admin.

Cause: UTC times are incorrectly set, or the server time is wrong.

Solution: Verify the timezone settings in WordPress. This is under Settings> General. You will specify your UTC time.
Eg: Pacific Standard Time is UTC-8. (Meaning: UTC time subtract eight hours)

If you do not know your UTC time, check out the chart on the bottom of this page:
http://www.scc-ares-races.org/utcchart.html

If this is not the problem, you need to check the local date and time on your server.
If you have a hosting provider, you may need to contact them if you suspect the time is wrong on their servers, however this is unlikely since hosting companies are usually very careful about these thing. Wrong date and times actually cause a huge amount of problems communicating securely over the Internet.

If it is your own server, research changing the time in your native operating system.

Did this help you? Let us know, and others, by commenting below.