The term used by high performers within the business and entrepreneurworld, who wakes up at 04.00 in the morning, that refers to the period between 08.00 and noon. Aftermoon is followed by the afternoon.
I was working on the strategy in the morning, and when the staff came in in the aftermoon, we could start the plenum discussions.
The time after midnight and before dawn.
This word plays with the sound and meaning of its opposite - as afternoon is the time after mid day, aftermoon is the time after midnight.
I'm so tired, I went to sleep last night at 2:00 aftermoon.