The time shown on the ticket is, as far as I know, always local time as it will apply when the flight departs. In particular, I wouldn’t expect a ticket to be sold with a time quoted in EST for flight on a day on which daylight saving time was in force. The change in time of your ticket was probably for the airline’s operational reasons and the start of daylight saving was almost certainly a coincidence.
However, in any case where you’re uncertain about this, you should check with your airline, not ask random people on the internet to guess for you.
Yes, flight departure times for normal passenger flights are always shown in official local time, which follows DST changes according to the local rules.
Credit:stackoverflow.com‘