Why is the conversion from seconds to date time string so slow?

[mackpei]

Hi,

I have a performance issue concerning the conversion
from C's time_t (seconds since 00:00:00 GMT Jan. 1,
1970) to a date time string like CCYYMMDDHHMMSS.

I use EXSLT's Date library (add, duration, ...) to do
this conversion. It works, but the performance is very
poor (e.g.: 22 minutes for 3200 records).

XSLT is generated by Altova MapForce. I am sure the
performance loss is caused by this conversion, because
if I remove the mapping, the file transformation is
quite quick (40 seconds for the same 3200 records).

Can anyone over there give me some clues?

TIA

Mack