Yes, that is a standard problem in DAX, since it has no native concept of next record or previous record.
The standard solution is to store the value in the record you're starting from in a VAR
VAR current_time = SELECTEDVALUE(mytable[mytime])
and then lookup the other value you want to compare it with.
if the records are sorted and you want to compare to the next record it's often simpler to user power query to add a numerical index. Then you can get the current index and just add 1 or subtract 1.
but if that's not practical you can use FILTER possibly to find the matching record you want to compare to and retrieve the values from that.
Did this post answer your question? Mark it as a solution so others can find it!
Help when you know. Ask when you don't!
Join the conversation at We Talk BI
find out more about me at Slow BI