Canadian-Egyptian Mohamed Fahmy, Egyptian Baher Mohamed and Australian Peter Greste were sentenced to up to 10 years in prison in July 2014.
Their convictions for spreading false news were overturned and they were freed in February to await retrial.
Mr Greste was deported to Australia and is on trial again in absentia.
The journalists strenuously deny collaborating with the Muslim Brotherhood, which the Egyptian government considers a terrorist group, after the overthrow of President Mohammed Morsi by the military in 2013.
At a hearing on Sunday, the journalists were told the verdict would be delayed until 29 August.
An Egyptian court has again delayed a verdict in the retrial of three al-Jazeera journalists convicted of aiding the banned Muslim Brotherhood.