Re: SELECT and DATE Function question

"Aaron Bono" <postgresql(at)aranya(dot)com> writes:
> Use:

> select start_date + (cast(number_of_days as text) || ' days')::interval from
> blah

This is a pretty awful way to do it, much better is

select start_date + number_of_days * '1 day'::interval ...

which reduces to basically one multiplication instead of conversion to
text, text string append, parse interval string value (relying on a
couple of undocumented cast abilities).

But the real question here is whether you actually want sub-day
precision in your result. Should the column have been 'date' rather
than 'timestamp' to begin with? If not, what behavior are you expecting
at DST boundaries?

regards, tom lane