In this NOTAM below, the valid time is "2006280446-2007312359EST".

EST does not appear in the FAA NOTAM contractions list.

enter image description here

I assumed this EST meant "Eastern Standard Time", but that conflicts with the information shown below in ForeFlight.

This is what ForeFlight shows for the same NOTAM: enter image description here

What does this "EST" mean?

  • $\begingroup$ In your ForeFlight screenshot, look at the word directly before "CREATED" in each of the NOTAMS. $\endgroup$
    – Ralph J
    Commented Jul 7, 2020 at 3:13
  • $\begingroup$ @RalphJ true, and getting an FAA-source is much easier to defend than a private software product's interpretation. $\endgroup$ Commented Jul 7, 2020 at 20:09

2 Answers 2


If the NOTAM duration is expected to return to service prior to the End of Validity time, the time is expressed by using a date-time group followed immediately by EST (estimate). Any NOTAM that includes an EST must be canceled or replaced before the NOTAM reaches its End of Validity time. If the NOTAM is not canceled or replaced, it will expire at the end of validity time regardless of EST.

Reference: https://www.faa.gov/documentlibrary/media/order/notam.pdf#page=7

  • 1
    $\begingroup$ Welcome to aviation.SE! Please use the quote formatting for direct quotes from other sources; apart from being good practice it helps people who use screen readers and other tools. $\endgroup$
    – Pondlife
    Commented Jul 6, 2020 at 22:21
  • 1
    $\begingroup$ #page=7 would allow you to link the specific page in the .PDF also. Ie. faa.gov/documentlibrary/media/order/notam.pdf#page=7 $\endgroup$ Commented Jul 7, 2020 at 14:43


Oddly, this isn't stated explicitly in JO 7930.2, Notices to Airmen (NOTAM).


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