You can use the DATEDIFF() function to get the difference between the dates you want.
I would suggest changing the date formats in the datasource. This way it will make things a lot easier to do in Tableau. Tableau likes clean and efficient data. So take that into consideration when connecting to datasources.
You need to make your date fields at datetime format
Then using DATEDIFF() you can get the difference in seconds like this, below logic will return difference in seconds.
Once done then create a calculated field using below logic and use a custom number format of 00:00:00:00 (drop the first 0 to get rid of leading 0's for days)
IIF([Seconds] % 60 == 60,0,[Seconds] % 60)// seconds
+ IIF(INT([Seconds]/60) %60 == 60, 0, INT([Seconds]/60) %60) * 100 //minutes
+ IIF(INT([Seconds]/3600) % 24 == 0, 0, INT([Seconds]/3600) % 24) * 10000 //hours
+ INT([Seconds]/86400) * 1000000 // days
Drag this field in canvas and check
Let us know if this help.
I was not the original poster. I would suggest replying to him and not me.
Oh Sorry Robert. Mistake.