BuddyPress.org

I know this thread is old, but I want to help those that are in the same boat as I am in while searching for this issue on Google, I hope it is also pertinent to this thread fully as I believe these issues are linked together.

I was having an issue with this too, where the activity streams on the home page were showing times that are 7 hours off because of GMT time being 7 hours off from me.

This problem can easily be fixed by setting your WordPress’s main timezone settings to something like -8 instead of the city name ie; Los Angeles.

But I could not go this route because I’m currently using Ajax Event Calendar plugin, which requires the timezone to be a city name for some weird reason. Thus I had two plugins that wanted two conflicting things.

This is the fix I came up with that seems to work just fine for me : )
In buddypress: \bp-core\bp-core-functions.php
Find: function bp_core_time_since
Change: $newer_date = ( !$newer_date ) ? strtotime( bp_core_current_time() ) : $newer_date;
so that bp_core_current_time() becomes bp_core_current_time(false)

This passes over to the bp_core_current_time() which defaults as true which sets it to automatically handle the activity time differences as GMT instead of your time zone.

I’m not a WordPress pro but it looked like you could just hook into this function if you wanted to or override it, but this was the route I knew how to take.