Subject Re: [firebird-support] External table, Timestamp field value padded?
Author Dimitry Sibiryakov
> Why is the Timestamp field value padded with 'zero' when it is combined
> with (var)char fields?

Every value in external tables is aligned. And this alignment depends
on data type. Timestamps are aligned to 8 bytes.
For details you can search for thread with subject "Alignment of
ISC_TIMESTAMP" in firebird-devel list.