Here is the breakdown with my thoughts on how long it usually takes.
Design and Concept
Recent assignment : 2 hours My best guess of usual time: 2-3 hours, sometimes more
Pre-painting
Recent assignment: 2 hours Usual time: 2 hours is about right
Layout
Recent assignment: 2 hours Usual time: sounds about right
Calligraphy
Recent assignment: 2 hours Usual time: 2 - 4 hours depending on length and difficulty
Portrait/Badge
Recent assignment: 2 hours Usual time: 2-5 hours depending on medium
Illumination
Recent assignment: 4 hours Usual time: 4-6 hours depending upon complexity
Details
Recent assignment: 1 hour Usual time 1-2 hours
Packaging
Recent assignment: 1 hour Usual time 1 hour sounds right