A veteran meets the service requirements of this section if such veteran served in the active military, naval, air, or space service—
(1)
(1)#
for ninety days or more during a period of war;
(2)#
during a period of war and was discharged or released from such service for a service-connected disability;
(3)#
for a period of ninety consecutive days or more and such period began or ended during a period of war; or
(4)#
for an aggregate of ninety days or more in two or more separate periods of service during more than one period of war.