Looking at my post history,your deduction actually makes sense to me, I posted 3 posts before 9 pm forum time and other posts just after,at least it gives me an idea on how the bot works. Thanks for answering.
It's not 9 o'clock like him said, I'm pretty sure about the time that bots count my posts, because I always finish all 5 posts. All posts are completed before 7 pm, they will be counted on that day (according to the forum time), posts after 7pm, they will be charged the next day. You can check your post again on it 
I believe it is correctA full quote of what I said seems appropriate (with emphasis added):
It means that all posts made after 9:00 PM forum time will be counted for the next day because it's already a new day for the bot. But there is also a sort of middle ground since actual counting depends on when exactly the bot queries the forum. Technically, it doesn't matter so much when you make a post as when the bot counts it. Put differently, if it counts your posts after 9:00 PM, they will be counted toward the next day even if you posted them earlier
Regardless, the bot correctly counted my posts by yesterday's evening, so the issue is kinda solved (apart from the wrong post count on December 22). Still, it would be very nice and welcome if Yobit added a button to the panel with which we could force the bot to check our post counts, say, once every hour (to prevent abusing the button). Even being able to use this button once a day could help us better understand where we stand
What do you guys think?