What does 'EST' at the end of a NOTAM's valid time mean? In this NOTAM below, the valid time is &quot;2006280446-2007312359EST&quot;.
EST does not appear in the FAA NOTAM contractions list.

I assumed this EST meant &quot;Eastern Standard Time&quot;, but that conflicts with the information shown below in ForeFlight.
This is what ForeFlight shows for the same NOTAM:

What does this &quot;EST&quot; mean?
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