In Firedbird are there any date/time function as same as in ORACLE or
MSSQL? Do it allow to add or substract between 2 dates? In MSSQL I
used DATEDIFF function to find out a differences between 2 dates. Any
functions in Firebird do like this??? If not, it means that I have to create
UDF myself, right?
Sorry for asking many questions. I'm a newbie in Firebird but I have to
finish my project soon.

Thanks a lot.
Arvee