Times can vary due to individual animals, solutions, sperm concentrations and temperature. From our data and JC Gerhart (1980; pages 133-316; in "Biological Regulation and Development," vol II; Plenum Press, NY; Goldberger RF, editor)
Sperm and egg contact: time zero
Calcium wave and cortical granule breakdown (exocytosis) ~starts at 3-4 min after insemination (lasting 3 min)
Gravitational rotation: ~10 min after insemination (all times below are "after insemination")
Cortical contraction (pigment moves toward animal pole--not cortical rotation; contraction is transient): ~10-20 min
Second polar body extrusion: ~20-25 min
DNA synthesis (S phase): ~27 min
Cortical Rotation produces Grey Crescent (latter is very hard to see): ~46-60 min
Pronuclei contact each other: ~49 min
Mitosis: 75 (takes about ~15 min)
Cleavage: ~100 min