Thanks for letting us know about this issue.
This is happening because the server is using the UTC time zone to index all your post in our database. So if you live 6 hours behind UTC time, posting at 8 PM would make it 2 AM the next day in UTC time. Thus the date will be one day ahead.
Indexing in a standard time zone like UTC is necessary because we have queries like Fresh feed and sorting by date...etc. However, this pose a problem for the 365 project as you all have noticed. The team is working on a scheduler to solve this issue. I will update this thread when we have more progress on this issue.