Quote Originally Posted by fargoman View Post
So if you have a flight on a Sunday at 3pm....is this an exact 24 hour time period where you need to test at Saturday no later the 3:00 on your covid test? I am the assuming you should test at 1 or 2:00 the previous day (Saturday in this example) to be safe. But what happens if your flight if delayed several hours putting your covid test several hours past the 24 period in this case? We all know flights can get delayed back to the states in the winter. Is the test no longer valid? Am I crazy for asking about this scenario?
This page:
https://www.cdc.gov/coronavirus/2019...travelers.html

Contains the following:

Why does the Order specify 1 day rather than 24 hours? What is considered 1 day?
The 1-day period is 1 day before the flight’s departure. The Order uses a 1-day time frame instead of 24 hours to provide more flexibility to the air passenger and aircraft operator. By using a 1-day window, test acceptability does not depend on the time of the flight or the time of day that the test sample was taken.

For example, if your flight is at 1pm on a Friday, you could board with a negative test that was taken any time on the prior Thursday.