[SQL] Time related question...

I have a database that tracks the service calls we do. In the database
are abstime values for:
dateentered
dateclosed
dateassigned
datecontacted

I have perl scripts managing the interaction between our web site and the
database.

My question is: what is the SQL statement that will allow me to find:
1) a list of the calls where the difference between the dateentered and
dateclosed is less than (say) 3 days.

I have tried:
Select * from servicecall where (dateentered <#> dateclosed) #<= 3 days;
Select * from servicecall where (dateclosed - dateentered) #<= 3 days;
Select * from servicecall where (dateentered <#> dateclosed) #<= @3 days;
Select * from servicecall where (dateclosed - dateentered) #<= @3 days;

Any suggestions?

Thanks.

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Kevin Colagio, Systems Administrator, Webmaster,
and perpetual student.
kcolagio(at)wc(dot)eso(dot)mc(dot)xerox(dot)com
Personal URL:<http://www.rit.edu/~kdc5072>