Difference between last date and next one

[newkingdom]

Hi, I am completely new to power bi. I have a table with appointments for customers by their id. each id number can have multiple appointment dates.

i am trying to find the number of days since the last appointment the patient had and their next appointment. 

Please tell me how I can achieve that. Thank you. 

[newkingdom]

	data				results
	id	date			id	days from last appointment to today
	101	8/20/2019			101	7
	101	8/21/2019			102	32
	101	8/22/2019			103	62
	101	8/29/2019
	102	8/24/2019
	102	8/25/2019
	102	9/26/2019
	103	8/27/2019
	103	8/28/2019
	103	8/29/2019
	103	10/30/2019

Something along the lines of this basically

[Ashish_Mathur · Accepted solution]

Hi,

Hope this helps.

[newkingdom]

Thank you so much. Just a a follow up though, some of the tables only had one date and so the numbers are huge, like 43000. How can I add the condition that if 2ndlastday does not exist, then do not subtract or maybe just return the date?

[Ashish_Mathur]

Hi,

Try this measure

=IF(ISBLANK([Second last date]),BLANK(),[Days since previous appointment])

[Ashish_Mathur]

Hi,

Share some data and show the expected result.