Django has a contrib package called "django.contrib.humanize". 
#Add this to your INSTALLED_APPS, 
#then use 
{% load humanize %} 
#in your template, after that,
you can use "value|naturaltime" template tag. "value" will be your date

ref : https://stackoverflow.com/questions/40345450/how-to-display-human-time-x-days-ago-or-now-in-django-admin