Using CURRENT to Select a Range of Records?

I is possible to use CURRENT in a select statement to select all records that are less than 24 hours old, or 30 days old? I have a table with a DATETIME field in it (YEAR TO SECOND), and want to return records from the past 24 hours (not just the current day, but 24 hours), and a similar query that returns records from the past 30 days. Is there a way to use CURRENT to do this instead of building "CCYY-MM-DD HH:MM:SS" by hand. Thanks In Advance.