How to get the difference between two dates in days and hours?

Hello Guys

I have two variable in this format:  dd/mm/yyyy hh:mm:ss

StartDate = '01/11/2017 13:00:00'  
EndDate  = '02/11/2017  13:30:00'

How to get the difference between these two dates in days and hours

ddd  hh:mm:ss
001   01:30:00

Thanks
Alex