Public School on Saturdays in Vietnam?

 It's not universal or the same everywhere, but it's common enough that it trips up expats:

• Primary schools: increasingly moved to a 5-day week as more schools adopt full-day (2 sessions/day) schedules, but some still run half-day Saturday sessions, especially at schools without full-day capacity.
• Secondary and high school: Saturday morning classes are quite common — often used for supplementary lessons, exam prep, extracurriculars, or to hit the required weekly instructional hours, since Vietnamese curricula pack in more content per week than a typical US school.
• It varies school by school and district by district — some have gone full 5-day, others haven't. There's no single national rule locking every school into 6 days.

If you land a public school job, don't assume your workweek is Monday–Friday. Ask directly during the interview whether the schedule includes Saturday mornings, since it affects your weekend planning.