Re: Inconsistent time interval formatting

That won't really help.  The fundamental point here is that '1 day' is
not the same concept as '24 hours', because of DST changes; and the
interval type treats them as different.

If you don't care about that, you can use justify_hours (I think that's
the right function) to smash them to the same thing.

But I suspect the OP's real complaint would be better solved by use of
to_char() to produce an output format that includes zeroes instead of
dropping fields that are zero.

                       regards, tom lane