Question: How do I check if the timestamp date of a record is before midnight today?

datediff is driving me nuts...

Answer: 
Here is how to get 0 hour of today in SQL

```
SELECT (CAST(FLOOR(CAST(GETDATE() as FLOAT)) AS DateTime))

```

Just compare your time against that.

Don't use varchar casts since they are slow.

[Check this list](https://stackoverflow.com/questions/202243/custom-datetime-formatting-in-sql-server#202288) for more date time help.
Do you mean that the datatype of the column you ate using is "TimeStamp", not dateTime or smalldatetime ?

If so, then you're out of luck. This datatype has nothing to do with dates or times (it's really misleading...) It's just guaranteed to be chronologically unique and sequential... But there's no way ot compare it with a datetime 

<http://msdn.microsoft.com/en-us/library/aa260631(SQL.80).aspx>

<http://www.sqlteam.com/article/timestamps-vs-datetime-data-types>