What is the generally accepted practice, SQL, for having to Parameterize by DATE but using a DATETIME data type

So my Date Parameter seems to work fine...but I think I'm missing some data. My database column type is defined as DATETIME. And I want to be able to select my report by a date range.

So what is the generally accepted practice for incorporating this? Convert my database field to a DATE within my WHEREE Clause? Add a DateTime Parameter using some DateTime math to get the previous day's DateTime last second?

Just wondering what the generally accepted practice is.

Thanks for your review and am hopeful for a reply.