Gosh, it depends on your hen, really. The PROCESS of laying lasts less than one minute. Hanging around ahead of time, or afterward, is purely optional and up to the pullet or hen.
I've copied this from another source:
Section of oviduct Approximate time egg spends in this section Functions of section of oviduct
1 Funnel (infundibulum) 15 minutes Receives yolk from ovary. If live sperm present, fertilization occurs here (commercially produced table eggs are not fertilized)
2 Magnum 3 hours Inner and outer shell membranes are added, as are some water and mineral salts
3 Isthmus 1 hour Albumen (white) is secreted and layered around the yolk
4 Shell gland (uterus) 21 hours Initially some water is added, making the outer white thinner. Then the shell material (mainly calcium carbonate) is added. Pigments may also be added to make the shell brown
5 Vagina/cloaca less than 1 minute The egg passes through this section before laying. It has no other known function in the eggs formation
Hope that helps!