What's a good way to check if two datetimes are on the same calendar day in TSQL?

Question

Here is the issue I am having: I have a large query that needs to compare datetimes in the where clause to see if two dates are on the same day. My current solution, which suck

Answer 1

where
year(date1) = year(date2)
and month(date1) = month(date2)
and day(date1) = day(date2)