An enro is a passage of time based on proeathan time keeping. It is a standard passage of short measured time that make up a day equivalent to human hours. An enro is approximately six hours in length. A proeathan day is made up of four enro with several smaller measurements of time breaking it up for more precise time keeping but is largely only used for record keeping or computers. In conversation proeathans speak in enros.
Proeathans measure time in greater chunks because of their long lives so time has less weight than human time keeping. There is no such thing as a second in proeathan time keeping but there are 'minutes' so to speak. Proeathan clocks would not in any way resemble human clocks with a round face.