Some higher courts are to take shorter holidays this year because of pressure on the system.
Chief Justice Mrs Justice Susan Denham has said the Supreme Court and the Court of Criminal Appeal will sit during September.
She said: "This is a pro-active measure by the judges of these courts to tackle the significant delays before an appeal can be heard.
"It is part of our ongoing efforts, and is an interim measure, to lessen delays, before the introduction of a Court of Appeal, which would provide permanent and sensible relief of the current logjam."
The Supreme Court currently has a waiting time of four years for an appeal.
Delays for appeals before the Court of Criminal Appeal are over 15 months.
Minister for Justice Alan Shatter has welcomed the decision and said the long waiting times had "been of concern".
He said: "This measure on the part of the judiciary will also alleviate the delays and help to ensure that citizens' right of access to justice is upheld."