Thanks guys for all your help, much appreciate! All I needed to do was remove the data type 'date' that I had in my prompts and set the format pattern to YYYY-MM-DD and it's working like it should.

I've solved the problem with the prompts. (select sum(ass.laborhrs) from assignment ass where ass.laborcode = l.laborcode and ass.scheduledate between to_date(#prompt('StartDate','date')#,'YYYY-MM-DD') and to_date(#prompt('EndDate','date')#,'YYYY-MM-DD')) as assignment_ure (select sum(lt.regularhrs) from labtrans lt where lt.laborcode = l.laborcode and lt.orgid = l.orgid and startdate between to_date(#prompt('StartDate','date')#,'YYYY-MM-DD') and to_date(#prompt('EndDate','date')#,'YYYY-MM-DD')) as delovne_ure, (select count(calnum) from workperiod where calnum='KOPA'and workdate between to_date(#prompt('StartDate','date')#,'YYYY-MM-DD') and to_date(#prompt('EndDate','date')#,'YYYY-MM-DD') and shiftnum='HOLIDAY') * 8 as stevilo_praznikov_ure, (select sum(workhours) from workperiod where calnum='KOPA'and workdate between to_date(#prompt('StartDate','date')#,'YYYY-MM-DD') and to_date(#prompt('EndDate','date')#,'YYYY-MM-DD')). Here is my SQL select that I'm using: select laborcode, I'm using to_date form, but I'm not sure if it is the correct one. I'm not really sure what's wrong.I tried to change the format but it didn't helped. SQL20448N '1993' cannot be interpreted using format string 'YYYY-MM-DD' for the TIMESTAMP_FORMAT function. UDA-SQL-0144 An arithmetic exception was detected. I'm having trouble with an error that says:

Cognos sql prompt