Measuring time in a world without a Moving Sun/Moon?

[Mcdt2]

A friend of mine is making a campaign world of his own for our next game, and has been revealing some bits and pieces of it to me slowly. Of note is that, in this cosmology, the Sun and Moon are literally the bodies of the Divine Entities of the same name. However, the exact nature of the world is... odd, because of it. To quote my friend

There was originally two gods. One was a being of fire and light, the other a being of cold and darkness. They fought endlessly, being opposites, but were also fascinated with each other. Eventually, they came to love each other, and in their union created the world as a bridge between their two planes. Thus, the sun lies always to the north, and the moon always to the south, and the climate becomes warmer the more northerly you go, and colder the further south.
...
The Sun King and the Moon Queen are the eldest and most powerful deities, and are greatly respected and feared. The sky is their dance floor and the stars are their courtiers.

Now, I'm sure he has something set up for this already, but I'd like to hear what the playground thinks of this. What would the ramifications, physically speaking, of such a world? How would they tell time when Sun and Moon don't move? What would sleep patterns look like?

[GreatDane]

One of the campaigns I'm playing in is currently visiting a world of eternal night. The population sleeps whenever they want based on their own personal rhythms; because of this, about a third of the city is asleep at any given time.

Alternatively, you could just wait for your daily-charge magic items to refresh.

[Galen]

I suggest inserting a plot device in the shape of a plant, insect or animal with a steady cycle of life/activity. This can be used to measure time. Or maybe a natural phenomena like tides, or a geyser like Old Faithful.

"When did the battle take place?"
"Twenty five cherry blossoms ago."
"How long did the battle last?"
"Three rolls of the tide"

Now, a valid question is, if there are no seasons, why does the cherry blossom have a steady life cycle? Well, heck, it's a magical fantasy world, so, like, who knows, right?

[Dunditschia]

Without magic, that would lead to a world where only a small strip of land between the edges can be lived in. The very stones would melt at the sun-side, and air would begin to freeze at the moon-side. Keeping track of time would probably be the last of your problems, living in a world of eternal dusk.

Mechanical clocks would still work though, as would any clock involving sand or water, so it's probably not all that different. There's just no firm day-night cycle to refer back to.

[Galen]

Without magic, that would lead to a world where only a small strip of land between the edges can be lived in. The very stones would melt at the sun-side, and air would begin to freeze at the moon-side.

That is assuming the Sun is your only, or main, source of heat.
At least on a fiction level, one can envision a world where the sun merely provides light, plus possibly a small amount of heat, and the heat comes from different sources, such as volcanic, geothermal, or radioactivity. The sun side will be noticeably warmer, and the dark side colder, but both can be liveable.

[Oracle_of_Void]

Are radioactive isotope clocks out of the question?

[zabbarot]

Your best measure of time might actually be the length between sleep. I mean... you don't have day and night, you don't have seasons it doesn't leave a lot that can be tracked by an individual. But how long someone is awake before getting tired could be more or less standard.

In a preindustrial society time is mostly important for knowing things like when to plant your crops and when certain jobs need to get done. Your sort of constrained by the day/night cycle, and eventually you're gonna run out of light to get stuff done by. Without the cycle time doesn't really matter as much. You can plant crops whenever you want, they'll be fine. You harvest them when they're done growing, you don't have to worry about an early frost ruining them.

So taking that out time is purely a social construct (well the measurement of it) The units are whatever they agree on, but the only purpose it serves is to help people coordinate and plan ahead. And really without seasonal changes to plan around things are probably fairly ideal. I mean, you need time to know when to show up at Bill's house for the party, but you don't need months to know that you're growing season is about to start or end. Most of the world is pretty static, so the other big measurement of time could actually be lifespans. I wouldn't really expect most people have any sort of reliable measurement of their age though.

[brian 333]

Spelunkers tend to sleep longer in the absence of a day/night cycle. 12 hours of sleep followed by 12 hours of activity is reported by cavers on long term expeditions.

[Everyl]

The Sun King and the Moon Queen are the eldest and most powerful deities, and are greatly respected and feared. The sky is their dance floor and the stars are their courtiers.

This sounds to me like the stars still move in the sky. If they move in a predictable pattern, they'd be used to reckon time. If you assume that only the sun and moon are fixed, and they're fixed roughly along the planet's axis of rotation, then the stars would still wheel across the sky. I'd imagine people would count "days" by the risings and settings of a particularly noteworthy and visible constellation, even if it doesn't map well to their sleep schedules.