What is the DTAC 72-hour rule regarding arrival in Thailand?

Time of arrival - what else?

You can fill out and submit the TDAC (Thailand Digital Arrival Card) starting three days/72 hours before your planned entry; it only takes five minutes on your home computer, it takes a little bit longer on the smartphone

Every non-Thai citizen is required to have completed the TDAC, regardless of whether they have a visa or an existing stay permit.

It's important not to fall for fraudulent websites that charge a fee for the TDAC—they're all fake. The TDAC is free.

Open the official website and simply fill it out pro forma.

Create a note or a Word .doc document on your computer with the requested information, e.g., passport number, name and address in your home country, primary address in Thailand, and so on.

Then, starting three days/72 hours before your planned entry, you can copy and paste the information into the TDAC—it only takes two minutes!

NOTE: The "Visa Number" and "Departure" from Thailand are NOT required fields; you can leave them blank.

BUT: As soon as you click on one of these fields not marked with a red *asterisk or start typing, an error message will appear if you don't fill out anything else. Then you would have to cancel everything and start over.

The TDAC confirmation will reach your email inbox shortly after submitting the form. You should print out this email confirmation, as it contains a QR Code

If you don't have to present the printed TDAC at the immigration counter, it doesn't mean anything - the border official will see the TDAC you submitted on his/her computer screen as soon as they scan your passport, so they won't ask again

The TDAC is not a visa, it is only an information you give Thai authorities about your person, your arrival information and your place of stay.

Assuming you haven't completed a TDAC, they won't let you enter the country but will send you back to the terminals with a request to submit it.

It says on the form 72 hours of your arrival, not departure.

It's an arrival card so it's within 72 hours of ETA at a Thai border.

TDAC. Day of arrival.

To select your arrival date, there's a calendar to choose the day. That calendar only lets you choose a date within 3 days as your arrival date. 72 hours isn't really relevant. It's any time within 3 days of your arrival.

72 hours before you land in Bangkok