At 07:46 AM 1/04/2004 +0000, you wrote:

>Hi,
>
>I'm converting an application from IB 5.6 to FB 1.5. This part of a query
>was working under IB 5.6
>
>.... f_round('NOW' - hi_vvd, 0) AS ELAPSED_DAYS ....
>
>Under FB I get "Expression evaluation not supported" error.
>
>I tried already NOW with double quotes, without quotes, but it seems NOW
>cannot be used to calculate the number of days.

Yes, but since IB 6 you have to cast the predefined date literals, viz.
.... f_round(cast ('NOW' as timestamp) - hi_vvd, 0) AS ELAPSED_DAYS ....

or you can replace it with

.... f_round(CURRENT_TIMESTAMP - hi_vvd, 0) AS ELAPSED_DAYS ....

/hb