Possible Clues:

• Former head of education was in at the appointed hour
• I'm heading for exit after old bag becomes ex
• The result of synchronising watches once
• Past it?
• Former outcome of synchronising watches?
• Former employee finally comes in punctually
• The ex, I note, has gone off me
• Old European entered punctually
• Somebody getting porridge late
• How often a singular event happens (2 words)