I dont understand the logic of below…could someone give 2 examples and explain how to define a period? I am still not sure I get it after I checked all the related questions posts…
For example, from 4/30/2012 to 5/2/2012 consider as one period, but it only has 2 days? or we do 4/30/2012-6/2/2012?
Thank you in advance!!
‘‘More concretely, given a month
churn ), we’ll count the number of subscriptions where
start_date comes before the first day of
ym , and where
end_date is after the last day of the previous month (which is to say that the
end_date is greater than or equal to the first day of