30 day trailing problem

Hello, fairly new to Power BI and I hope to get the answer to if my problem can be solved or it can´t by using power bi.

Problem: 

Students absent 1 class should be reported after 30 working days after first absent class. For example student is sick day 5 and on day 35 (working days) it should be reported. Student nr 278 is last sick or absent on day 7 that should be reported day 37 after absent class. 

I want to know if it is possible to build a Power BI solution without an underlying database, just excel files to fetch data from ( probably using a starschema). That will send an indication when students are sick after 30 days. 

Ex 2: Student 1 is sick day 8 and absent from class day 17. Student 2 is absent day 16 and 17 and 18. 

Student 1 should be indicated day 38 and student 2 indicated day 46

Students must be unique and cant be grouped together. Preferably an email should be sent whenever a 30 day indication is hit (not a must)

(Hope I could write my question in a clear and easily understood way)