Ryanair customers are demanding to know which flights will be cancelled in the coming six weeks.
The chaos comes after the airline admitted it "messed up" with its pilots' holidays.
As a result, Ryanair has been forced to cancel up to 60 flights a day to the end of next month.
The company is facing compensation payments to pass-engers, which could cost it millions.
The Commission for Aviation Regulation ruled yesterday that there were no exceptional circumstances behind the cancellations.
Among those cancelled yesterday were eight flights affecting Dublin, including outbound trips to Amsterdam, Frankfurt, Nantes and Santander.
Inbound flights from the same destinations were also cancelled.
Confusion has reigned over the bookings that will be cancelled in the coming weeks, with the airline slow to let its customers know if their flights have been affected.
Ryanair marketing officer Kenny Jacobs said that all customers with bookings up to Wednesday have been informed.
"We've messed up in the planning of pilot holidays and we're working hard to fix that," he said.
However, there was a flurry of messages on Ryanair's social media pages yesterday, with customers desperate to know if their flights are going ahead.
Passengers have accused the airline of treating them "app- allingly" and demanded it publishes a full list of the flights to be cancelled over the next six weeks.
"This is an awful way to treat customers," Lee Bore wrote.
"You need to inform us now of every flight you are planning to cancel over the next six weeks and not give six hours, 12 hours or 24 hours notice. Leaving people stranded is not on."
Edina Moisin wrote: "You should publish a list of all cancelled flights, not keeping people wondering if their flights will be cancelled or not."
Grandmother Karen Litton was due to fly from Knock to Stansted to meet her first granddaughter this week.
However, the estate agent has been left devastated after Ryanair cancelled her flight.
"I'm heartbroken. I was due to fly over to meet my new granddaughter Margot on Wednesday," she said.
"I was going to spend a week with my daughter to help out as her husband is starting back to work after his paternity leave. We're all so disappointed."
Ryanair has blamed the disruption on the company changing its holiday year - which currently runs from April to March - to run from January to December.
It said the shift meant it had to allocate annual leave to pilots this month and next.
The Herald asked Ryanair for details of flights that would be cancelled for the rest of this week, but there was no response to queries.
However, 12 flights have been cancelled from today, including to and from Amsterdam, Brussels, Manchester, London, Bristol and Barcelona.
Ryanair is facing increased competition in the low-fares aviation market from relative newcomer Norwegian Air.
The Scandinavian airline recently said it has signed up 140 former Ryanair pilots.