Guam is 18 hours ahead of Los Angeles (PST), and 17 hours ahead during PDT. Guam uses Chamorro Standard Time (ChST, UTC+10). Los Angeles uses Pacific Time and observes DST.
When it's Monday 12:00 PM in Los Angeles, it's Tuesday 6:00 AM (PST) or 5:00 AM (PDT) in Guam.
Evening LA, morning Guam next day! 6:00 PM in Los Angeles is noon the next day in Guam. The date line creates scheduling challenges.
Guam is a US territory in the western Pacific. United Airlines operates direct flights from Los Angeles to Guam, taking about 12 hours.