How to find an interstellar species? Look for their clock.
I got to thinking about how an interstellar species would be all on the same page when it comes to time. The solution I came up with would be one or more beacon clocks placed near the center of their civilization.
This beacon clock would send out a signal. The inhabitants of this civilization would know its distance from this beacon clock. With that knowledge, they would know what time it is in their society.
