What is the shortest and the longest time you have seen someone go through the forgiveness process when the injustice is very deep? In other words, I am not talking about people who have been hurt but it is more of a passing anger and not a deeply entrenched anger from a profound injustice.
The shortest time to a successful forgiveness was observed in a scientific study of elderly women in hospice who had less than 6 months to live. They had deep hurts from family members and some of these hurts began decades ago. These courageous women only took 4 weeks to forgive the deep injustices, perhaps because they were trying their best to confront unresolved issues in need of resolution. The longest I have seen is a study of female incest survivors, who took on the average over a year to forgive. Here are the references to these two research studies:
Hansen, M. J., Enright. R. D., Baskin, T. W., & Klatt, J. (2009). A palliative care intervention in forgiveness therapy for elderly terminally-ill cancer patients. Journal of Palliative Care, 25, 51-60.
Freedman, S. R., & Enright, R. D. (1996). Forgiveness as an intervention goal with incest survivors. Journal of Consulting and Clinical Psychology, 64(5), 983-992.