Hello,
This event actually closed on the fifth. I suspect that you probably do not play in a time zone that properly matches your actual server's time zone. Is that correct? If you have mismatch like this, some of the server events won't display properly, as some of them are coded to display off of local time and some of them are coded to display off of server time. It looks like you're offset by about two hours, which is enough to push the date to the next "day".

Since it was found out Froggy closing early was just a visual bug and it was already closed during day 6, I have just one more question. Why this froggy was only 5-day one? I don't think I remember a froggy, that wasn't ful week (7 days) one. Having only partial week event makes it harder for players to decide should they need to take part in Froggy for next week. In my own case, I was late to take part, because I didn't have info about what events were on next (now current) week and was still doubting.

Having full 7-day Naruto's froggys in the future might get more people wiling to spend on it, since they know on wednesday at least should they need it. That would prevent this happening again at the same time.