If your course language is changed from English to Spanish, French, and other non-English languages the calendar date picker will no longer work properly. This means when selecting availability dates for assignments, quizzes, and discussion or setting a posting date for an Announcement the date you select from the calendar pop-up window will be incorrect. Canvas is aware of this problem, but there is no ETA on when a fix will be released.
Manually type in the date, YYYY-MM-DD HH:MM, opposed to clicking on the calendar icon to choose one.
Example: February 22nd, 2018 @10:PM would be 2018-02-22 22:00
The time, HH:MM, is typed in using a 24 hour clock so 8AM is 08:00 and 2:43PM is 14:43.