Timed Durations
Durations are usually measured in rounds, minutes, hours, days, or other increments. When the time of the effect’s duration is up, the energy or force empowering the effect goes away and the effect ends. If an effect’s duration is variable, the duration is rolled secretly by the GM so you don’t know how long the effect will last.
Whenever an effect’s duration is expressed in a standard unit that measures time, such as hours, days, or even years, it refers to those units as expressed in Pact Standard Time. Under this scheme, a day has 24 hours of 60 minutes each, and a year has 365 days (or 52 weeks). For more information about time and similar concepts in Starfinder, see Time on page 430.
Source
Core Rulebook pg. 270