extended for one year if the petition is filed when the PD is current. However,
the H-1 extension application can be filed in advance up to 180 days before the
current H-1 expires, so if possible, your friend may ask the employer to file
the H-1 earlier before the PD is current so that the H-1 can be extended for
another 3 years.
謝謝8老師!