Duration: P1Y2M3DT10H30M is 37017000 seconds
Seconds: 37017000 is P1Y2M3DT10H30M duration
Duration: -P120D is -10368000 seconds
Seconds: -10368000 is -P4M duration
Seconds: 1766503406 is P56Y5DT15H23M26S duration
Duration: P56Y5DT15H23M26S is 1766503406 seconds
Add should be PT0S: PT0S
Subtract should be PT0S: PT0S