How to check multiple consecutive absence in Fast Formula

If I have 5 absence entry of same absence type

how can I check in fast formula tat those are consecutive or not ?


Like

Absence 1 : 28.01 - 31.01

Absence 2 : 23.01-27.01

Absence 3 : 20.01-22.01

Absence 4 : 15.01- 18.01

Absence 5 : 10.01-14.01

So I will first check absence 1 and when I will get there is 2 consecutive absences from 23.01 and 20.01 , I need to sum duration for those as well.

How I can achieve this