What does date of issue mean on the Vietnam digital arrival card?

Date of issue means the day your entry document was issued, not the date you arrive. For an e-visa this is the date printed on the visa as the issue date, normally the day immigration approved it.

Your entry date goes in the arrival date field, and the validity dates of the visa go in the from and to fields. Take all three from the PDF so they match what immigration sees in its own system.

If you are visa exempt, there is no issue date. Choose the exemption option and enter the dates of your stay instead.

You complete the form free of charge at prearrival.immigration.gov.vn. If your e-visa has an error in the dates, fix that first, because immigration compares the card with the visa. Our Vietnam e-visa guide covers the basics.