TODAY and CURRENT? - Mailing list pgsql-general

I have a table with columns

datetime   timestamp,
value        float(8)

I want to delete rows 10 days older or 10 hours older by

delete from tablename where datetime < TODAY-10;
or
delete from tablename where datetime between CURRENT-10 and CURRENT;

So are there key words TODAY, CURRENT in PostgreSQL?

Thank you!