Why "Kerbal Time"?

[tstehler1]

6-hour days and 400-something-day years? How strange... I was very confused when my first launch of my new save file (a high-orbit satellite to detect incoming ballistic Class-E space rocks of death) displayed a mission time of almost a week. I thought it was a glitch, but every ship I launched did the same thing, and eventually I found the option to switch back to normal time, which I did. I'm just very used to how long a mission should take.

Does anyone know exactly why they did this? Or was it just a "why the heck not?" action by Squad? I'm not particularly mad about its existence or anything, since it can be very easily reverted, I'm just wondering if there was any particular reason for putting it in the game, and especially for making it the default setting.

Edited April 10, 2014 by tstehler1
Please read the bold text before telling me what to do :)

[Taki117]

I think it's more of an immersion thing. With Kerbin days being only 6 earth hours it was the logical choice because Kerbals wouldn't be measuring missions in Earth Time.

[Kasuha]

If you don't like it, go to settings and switch it to Earth days and years.

To me it makes more sense to count in Kerbal days and years, though. If for me the day is the time in which my planet makes one revolution, for Kerbals it should be the same - i.e. time in which their planet makes one revolution. The same for a year.

[tstehler1]

To me it makes more sense to count in Kerbal days and years, though. If for me the day is the time in which my planet makes one revolution, for Kerbals it should be the same - i.e. time in which their planet makes one revolution. The same for a year.

Isn't it already? Or are the two different measures of time completely misaligned?

[Tex]

Hmm... I must not be paying attention to my game, as I thought it was always measured in Earth-time... Is Earth-time or Kerbin-time standard?

[regex]

Does anyone know exactly why they did this?

Probably for the role-playing crowd. Or something. I switched it off because I find it annoying as hell.

[Superfluous J]

It's more than immersion or roleplaying. I don't see any benefit to measuring "days" as 4 rotations of Kerbin, or "years" as some random number of Kerbin orbits. I want Kerbin to be in the same place in its orbit every year, and I want sunrise to happen at the same time every day.

I'm in the opposite camp as Regex, I found being locked to a useless time paradigm annoying as hell and I'm happy to use "real" Kerbin time now.

And the best part? Now we're both happy!

[lammatt]

because a day is a rotation, a year is a revolution.

i thought this was common sense, perhaps i am wrong though.

[Godot]

Hmm... I must not be paying attention to my game, as I thought it was always measured in Earth-time... Is Earth-time or Kerbin-time standard?

Kerbin Time.

You can easily see it on a Mun-Mission ...

formerly you would make to to Muns SOI in ~6 hours ...

now you need one day for this

[TheDarkStar]

The wiki says 106 d 12 h 32 m 24.6 s for Kerbin's orbit time, but that's probably in Earth days.

[Godot]

Well, if a Kerbin year now is 427 Kerbin days, this seems to be correct

[tstehler1]

Probably for the role-playing crowd. Or something. I switched it off because I find it annoying as hell.

Same, and I also disabled it.

But wait, I may have missed something that I'm just now realizing. Since I now have the game set to 24-hour days and 365-day years... Does that mean that the sun rises/sets four times in each "day?" And does it mean that Kerbin actually performs more than one complete orbit in each "year?"

I thought the game would compensate for this... Now I'm torn between the two...

[AlexinTokyo]

Yes. Kerbin rotates on its axis once every six hours, so one Kerbal day is six hours. One Terran day is four Kerbal days.

I personally like the new Kerbal time, as it's intuitive within the game (a KSO has an orbital period of one day, Kerbin returns to the same place in orbit after one year).

You do need to be a little careful coming out of time warp, though, because it will jump from 1d 0h 0m to 5h 59m 59s instead of 23h.

[softweir]

Hmm... I must not be paying attention to my game, as I thought it was always measured in Earth-time... Is Earth-time or Kerbin-time standard?

It used to be Earth-time, but Squad softly and silently rewrote the clock to work in Kerbal time. There were quite a lot of posts discussing this in the suggestions forum.

[Guest]

This is very good, because it makes Kerbin's position along it's orbit consistent each year and each day. It's very important when planning launches/transfers to inclined orbits, you can shave off a whole lot of dV if you time your launch right.

[Superfluous J]

This is very good, because it makes Kerbin's position along it's orbit consistent each year and each day. It's very important when planning launches/transfers to inclined orbits, you can shave off a whole lot of dV if you time your launch right.

This is an important thing. Now you can say (for example, this isn't correct) "On day 173 of each year, you can launch from KSC at 4:15pm, turn into your gravity turn at a 60 degree angle on the navball, and just keep burning until your periapsis touches Moho's orbit"

[That guy who builds stuff]

It becomes very useful when you need to time a return in which the orientation or position of Kerbin is important.

[regex]

This is an important thing. Now you can say (for example, this isn't correct) "On day 173 of each year, you can launch from KSC at 4:15pm, turn into your gravity turn at a 60 degree angle on the navball, and just keep burning until your periapsis touches Moho's orbit"

This would never really be something you could do unless the planets were in resonance (AFAIK), which they're not. (E: It's also worth mentioning that you can do exactly the same thing with Earth-centric time because Kerbin measure is exactly one quarter of that) In the end, it's just another way of keeping time. What would work equally as well is simply using the UT as raw seconds. The other time formats are just human-readable. Kerbin-centric time is better for immersion, but Earth-centric time is easier to "math" (I guess, for me at least).

Edited April 11, 2014 by regex

[maltesh]

Well, if a Kerbin year now is 427 Kerbin days, this seems to be correct

Except it's not.

Since they pinned it to the sidereal rotation period instead of the solar day, the time of sunrise creeps back every day. Start a new game. Put something on the pad. Fast forward until sunrise. Note the time. Fast forward until Kerbin's gone a quarter of the way around its orbit. Wait for the sun to rise. Note that the sun is now rising about 90 minutes later in what is called a Kerbin "Day." Fast forward until Kerbin's gone halfway around the sun. Wait for the sun to rise. It's now rising three hours later in the "Day" than it was when you started the game. 3/4 of the way around, the sun is rising 4 hours, 50 minutes late. After one orbit, the MET clock's Kerbin days are a full day ahead of the rotation of the planet.

If that's what you want, fine. For me, if the clock can't consistently tell me how long it's going to be to sunrise or sunset on the surface of Kerbin because of its year-round slippage, I'll stick with the regular units of time.

[DMagic]

It's more than immersion or roleplaying. I don't see any benefit to measuring "days" as 4 rotations of Kerbin, or "years" as some random number of Kerbin orbits. I want Kerbin to be in the same place in its orbit every year, and I want sunrise to happen at the same time every day.

I'm in the opposite camp as Regex, I found being locked to a useless time paradigm annoying as hell and I'm happy to use "real" Kerbin time now.

And the best part? Now we're both happy!

Yeah, it always bugged me that the timer didn't match up to Kerbin's rotation. It does seem like this should be something you can change in the in-game settings menu though.

One thing to note is that a year is not, as the settings menu says, 426 days, it is 426 days and change. I don't know if they have any kind of leap-year system implemented, but as far as I can tell all of the orbital parameters are unchanged from their pre-0.23.5 values. So if there isn't any leap-year system the dates might eventually be off by a few days.

[LethalDose]

I prefer the new system, because one year now means Kerbin goes around Kerbol once. That by itself is worth it for me, because I don't have to back calculate what a rotation is.

[Fizwalker]

I'm going to guess that this only applies to the game after the update to the ARM... Um... Add-on?

[Brotoro]

Except it's not.

Since they pinned it to the sidereal rotation period instead of the solar day, the time of sunrise creeps back every day. Start a new game. Put something on the pad. Fast forward until sunrise. Note the time. Fast forward until Kerbin's gone a quarter of the way around its orbit. Wait for the sun to rise. Note that the sun is now rising about 90 minutes later in what is called a Kerbin "Day." Fast forward until Kerbin's gone halfway around the sun. Wait for the sun to rise. It's now rising three hours later in the "Day" than it was when you started the game. 3/4 of the way around, the sun is rising 4 hours, 50 minutes late. After one orbit, the MET clock's Kerbin days are a full day ahead of the rotation of the planet.

If that's what you want, fine. For me, if the clock can't consistently tell me how long it's going to be to sunrise or sunset on the surface of Kerbin because of its year-round slippage, I'll stick with the regular units of time.

Maltesh points out an important thing here, so I give unto him some kerbal snacks.

Sidereal time is not very useful for Joe Kerman on the ground at KSC.

[Superfluous J]

This would never really be something you could do unless the planets were in resonance (AFAIK), which they're not. (E: It's also worth mentioning that you can do exactly the same thing with Earth-centric time because Kerbin measure is exactly one quarter of that) In the end, it's just another way of keeping time. What would work equally as well is simply using the UT as raw seconds. The other time formats are just human-readable. Kerbin-centric time is better for immersion, but Earth-centric time is easier to "math" (I guess, for me at least).

You may be misunderstanding what I mean. Kerbin's day is 1/4 Earth's day but its year is not 1/4 Earth's year. To launch to Moho, Dres and Eeloo many people like to launch when you're at AN/DN, not when the launch window planner tells you to launch. You will be (well, should be, I haven't tested it in-game yet) always be there at the exact day of the year. And if you figure out what time of day to launch at that time of year and the angle so that you're perfectly in line with Moho's orbit, that same launch will work EVERY year at that date and time.

Since they pinned it to the sidereal rotation period instead of the solar day, the time of sunrise creeps back every day.

Brilliant, Squad. Though for my idea that won't matter. At the same time of year, the sun should be in the same place relative to KSC at the same time.

One thing to note is that a year is not, as the settings menu says, 426 days, it is 426 days and change. I don't know if they have any kind of leap-year system implemented, but as far as I can tell all of the orbital parameters are unchanged from their pre-0.23.5 values. So if there isn't any leap-year system the dates might eventually be off by a few days.

Yeesh, I hope not. THIS would ruin my idea.

Though I see no real reason to go back to Earth time. It'd be like really wanting to see all the units in miles, quarts, and pounds.

[boxman]

This is an important thing. Now you can say (for example, this isn't correct) "On day 173 of each year, you can launch from KSC at 4:15pm, turn into your gravity turn at a 60 degree angle on the navball, and just keep burning until your periapsis touches Moho's orbit"

I dont see how that works when Moho and other planets have a completely different orbital cycle. Even though kerbin will be in the exact same position moho will have moved relative to kerbin.