1. Stars...either a constellation that 'rises and sets' just like the sun would, or a single start that is nearby but still quite a ways away. Remember our sun drowns out much of the star scape to us, a rogue planet would have a very bright star sky. The passage of the milky way across the sky could be one usable example.

2. Life spans. This gets into the 'foot' being the kings foot for a unit of measure. A ruler's lifetime could be referred to as a unit of measure. Of course this means the unit of measure is inexact (so was 'foot'), but it is usable.

3. Moons. If they are available, a moons cycle is a great time tracker.

4. Arbitrary. 1 second is a relatively abstract concept (same as '1 meter'), as we've set that this is what a second is and we're using it (our second finds it's roots in early Sumerian culture where they divided things in to 6 sets of gods (one male one female) * 5 (number of fingers or number of man) = 625 = 60 seconds. Same root as 360 degrees and 12 * 2 hours in a day.

I guess the question of 'what does a civilization measure with time' becomes necessary to ask. Is time on a timeless planet really necessary? Is time nothing but arbitrary? If it's a 'slow' species (sloth?) it's possible the arbitrary unit they come up with is significantly longer for a second than a much more hyper race.

1. Stars...either a constellation that 'rises and sets' just like the sun would, or a single star that is nearby but still quite a ways away. Remember our sun drowns out much of the star scape to us, a rogue planet would have a very bright star sky. The passage of the milky way across the sky could be one usable example.

2. Life spans. This gets into the 'foot' being the kings foot for a unit of measure. A ruler's lifetime could be referred to as a unit of measure. Of course this means the unit of measure is inexact (so was 'foot'), but it is usable.

3. Moons. If they are available, a moons cycle is a great time tracker.

4. Arbitrary. 1 second is a relatively abstract concept (same as '1 meter'), as we've set that this is what a second is and we're using it (our second finds it's roots in early Sumerian culture where they divided things in to 6 sets of gods (one male one female) * 5 (number of fingers or number of man) = 625 = 60 seconds. Same root as 360 degrees and 12 * 2 hours in a day.

I guess the question of 'what does a civilization measure with time' becomes necessary to ask. Is time on a timeless planet really necessary? Is time nothing but arbitrary? If it's a 'slow' species (sloth?) it's possible the arbitrary unit they come up with is significantly longer for a second than a much more hyper race.

1. Stars...either a constellation that 'rises and sets' just like the sun would, or a single start that is nearby but still quite a ways away. Remember our sun drowns out much of the star scape to us, a rogue planet would have a very bright star sky. The passage of the milky way across the sky could be one useable example.

2. Life spans. This get's into the 'foot' being the kings foot for a unit of measure. A ruler's lifetime could be referred to as a unit of measure. Of course this means the unit of measure is inexact (so was 'foot'), but it is usable.

3. Moons. If they are available, a moons cycle is a great time trakker.

4. Arbitrary. 1 second is a relatively abstract concept (same as '1 meter'), as we've set that this is what a second is and we're using it (our second finds it's roots in early Sumerian culture where they divided things in to 6 sets of gods (one male one female) * 5 (number of fingers or number of man) = 625 = 60 seconds. Same root as 360 degrees and 12 * 2 hours in a day.

I guess the question of 'what does a civilization measure with time' becomes necessary to ask. Is time on a timeless planet really necessary? Is time nothing but arbitrary? If it's a 'slow' species (sloth?) it's possible the arbitrary unit they come up with is significantly longer for a second than a much more hyper race.

1. Stars...either a constellation that 'rises and sets' just like the sun would, or a single start that is nearby but still quite a ways away. Remember our sun drowns out much of the star scape to us, a rogue planet would have a very bright star sky. The passage of the milky way across the sky could be one usable example.

2. Life spans. This gets into the 'foot' being the kings foot for a unit of measure. A ruler's lifetime could be referred to as a unit of measure. Of course this means the unit of measure is inexact (so was 'foot'), but it is usable.

3. Moons. If they are available, a moons cycle is a great time tracker.

4. Arbitrary. 1 second is a relatively abstract concept (same as '1 meter'), as we've set that this is what a second is and we're using it (our second finds it's roots in early Sumerian culture where they divided things in to 6 sets of gods (one male one female) * 5 (number of fingers or number of man) = 625 = 60 seconds. Same root as 360 degrees and 12 * 2 hours in a day.

I guess the question of 'what does a civilization measure with time' becomes necessary to ask. Is time on a timeless planet really necessary? Is time nothing but arbitrary? If it's a 'slow' species (sloth?) it's possible the arbitrary unit they come up with is significantly longer for a second than a much more hyper race.