In MySQL is it possible to do a unique constraint for the date portion of a `dateTime` column?

For example if I had `2018-10-01 10:05:06`, the following would not be allowed `2018-10-01 11:00:00`, because it has the same date.

Currently my best solution is to separate the dateTime column in to a separate date and time column, and perform a unique operation on the date column.