Is it just the one I'm with or do VNese have some odd meaning of time. For example SHE must be late to everything. Everything will happen in 10 minutes...10 becomes one hour, ten hours, just depends. They invite you to attend, and oh by the way it's tomorrow.
Latin countries have a similar meaning of time. They tell you it will be done "Monday", but never tell you which Monday. You invite them to a dinner party at 7PM and they show at 10pm.
Would love to hear from some Vietnamese on this as well. Maybe, it is just a family thing in my family.