Even the time format is MM-DD-YYYY, the calendar of tasks is still DD-MM-YYYY. "Japanese is 7日5月, it means DD-MM"
Thank you for your report. I've been able to reproduce this issue and I've passed it to the developers.
For now, as a workaround, you could try to use dates such as 7/5 or 5/7.
Thank you !
This issue should now be fixed. Please let us know in case it persists.