Power Bi relationships

Coming from a database world it is very rare to have a timestamp as a linking field between tables.  In any case in your table A let's say for Country USA - is there 1 time stamp?  i.e. 1/1/17 00:00:00      

Let's pretend there is - then in Table C to link you would need time stamp 1/1/17 00:00:00       only - - no other timestamp would link - - and in my experience the timestamp is varying every record made down to the second or even less.

You may need to broaden the time interval to a date, without time, so that the linking will match - this can be done with calculated columns in both tables as part of your data model.