Colloquium papers: 20 minutes
Colloquium commentaries: 10 minutes
Speaker replies: 5 minutes
Symposium papers: 45 minutes
Symposium commentaries: 45 minutes
Speaker replies: 20 minutes
All run 3 hours.
The typical Symposium is two 45-minute papers and a 45-minute commentary, with 45 minutes left for discussion and replies.
Sometimes there are 3-paper, no-commentator Symposia and 1-paper, 2-commentator Symposia.
For Author-Meets-Critics, there are usually 2 45-minute 'criticisms' and up to 45 minutes for the author's reply.
For invited papers (usually two 90-minute sessions in a 3-hour slot): 40 minutes for the paper, 20 for the comments, 30 for reply and discussion.