It takes 2 working days for the Immigration to process the visa approval letter under normal processing time (or 1 working day under urgent processing time). The working days of the Immigration are from Monday-Friday, and working time from 9a.m-5p.m each working day. Click here for details of processing time and fee.
Besides the weekends, there are several off-working days (Vietnam holidays) annually in Vietnam that the agent and the Immigration do not work: National Lunar New Year (Tet Holiday), the 1st January, Hung Kings Commemoriations, the National Reunion day 30th April, the International Labor Day 1st May, and the National Liberation Day 2ndSeptember.