Vietnam visas are usually processed from 36 hours to 2 working days. We are here to help you get Vietnam visa on arrival in simple, fast and reliable 

Normal processing time: You will receive your approval letter usually 2 business days after we receive your payment. You can speed up the process by applying for same day or next day processing with additional fees.

For same-day processing: If you apply before 8 A.M. Monday to Friday (Vietnam time, GMT +7), you will receive your approval letter by noon of the same day. If you apply after noon, you will receive your approval letter by 5 P.M. Any application made after 5 P.M. will be processed by noon the next working day.
For time convert, please check http://www.timeanddate.com/worldclock/converter.html
More about Vietnam urgent visa information

Notes:

1. Processing times are given in working days, excluding weekends and public holidays. 
We normally do not want you, as our customer, to spend so much money to visa at weekend or holiday. We would suggest you delay your flight then you will have time to do normal visa into Vietnam.
In the case where you are in business and/or cannot delay the arrival then we will be happy to help. Read more about Vietnam visa at weekend

2. You can apply for your visa within 3 months of your intended date of travel.