Ho Chi Minh City is 7 hours ahead of Reykjavik
Best overlap: 8:00 AM to 11:00 AM in Reykjavik is 3:00 PM to 6:00 PM in Ho Chi Minh City.
Plan around 8:00 AM to 11:00 AM in Reykjavik, which is 3:00 PM to 6:00 PM in Ho Chi Minh City, to catch everyone during office hours. Since Ho Chi Minh City is 7 hours ahead of Reykjavik, the workdays overlap by around 3 hours; 8:00 AM in Reykjavik (3:00 PM in Ho Chi Minh City) makes a reliable recurring slot.