Msfs time

[jimjones]

My understanding of MSFS TIME


After selecting an airplane, location and weather one selects the time so that we have day or night for our flight. We are given a slider bar and + or - buttons to make that adjustment. The time entered becomes the LOCAL time displayed during flight and is reflected in the display above the slider bar. If we enter the time of sunrise we can see the sun peeking over the horizon just after flight.


After the flight the recorded time in the PROFILE is not what was set as the LOCAL time (above) but the actual time (from your watch or wall clock) you start and end your flight in Universal Time which is the actual time adjusted by your time zone and daylight saving time. The flight takeoff or landing will be recorded as DAY several minutes before sunrise and several minutes after sunset, else it will be recorded as NIGHT. The MSFS sky glow before sunrise and after sunset may be thought of as twilight, which was not accurate for either of two accepted twilight conditions, astronomical or Nautical.


But there have been times when adjusting the time bar through its full range the time display above the slider bar always shown black, even when entering an actual time of noon. This may be a sometime anomaly on my PC related to my internet disconnecting for short periods. These disconnects affect my flight with large stutters too.


Hopefully this is accurate info, if not please correct me.

 

[Tom Clayton]

The preview window in the Flight Conditions window doesn't always respond right away. I think it starts out at the current Zulu time. I can set up a flight from a location that is in daylight for real time and it's still black unless I adjust the time bar by a minute or so, but when I start the flight, everything's good. As for the log, it's known to have "issues." Whenever the "official" forum is back online, have a look there and you'll see plenty about that.

 

[FlyingsCool]

My understanding of MSFS TIME


After selecting an airplane, location and weather one selects the time so that we have day or night for our flight. We are given a slider bar and + or - buttons to make that adjustment. The time entered becomes the LOCAL time displayed during flight and is reflected in the display above the slider bar. If we enter the time of sunrise we can see the sun peeking over the horizon just after flight.


After the flight the recorded time in the PROFILE is not what was set as the LOCAL time (above) but the actual time (from your watch or wall clock) you start and end your flight in Universal Time which is the actual time adjusted by your time zone and daylight saving time. The flight takeoff or landing will be recorded as DAY several minutes before sunrise and several minutes after sunset, else it will be recorded as NIGHT. The MSFS sky glow before sunrise and after sunset may be thought of as twilight, which was not accurate for either of two accepted twilight conditions, astronomical or Nautical.


But there have been times when adjusting the time bar through its full range the time display above the slider bar always shown black, even when entering an actual time of noon. This may be a sometime anomaly on my PC related to my internet disconnecting for short periods. These disconnects affect my flight with large stutters too.


Hopefully this is accurate info, if not please correct me.

By FAA rule "Night" starts 1 hour after sunset (not last light), and ends 1 hour before sunrise.

 

[pilto von pilto]

By FAA rule "Night" starts 1 hour after sunset (not last light), and ends 1 hour before sunrise.

I was today-years old when I learnt that. Thanks.

Seems a little iffy but I'm sure the FAA knows better than a fat anonymous bloke on the internet shouting into the void.

 

[FlyingsCool]

I was today-years old when I learnt that. Thanks.

Seems a little iffy but I'm sure the FAA knows better than a fat anonymous bloke on the internet shouting into the void.

Well, I think it has to do with, they want "Night" to actually be night. Around here, last light is typically about an hour after sunset during the summer, so it's still pretty light out after sunset. Same thing with the other end of the day (or night, however you want to look at it ) I think the transition rate is quite a bit faster in winter, but, who wants a rule that changes over the course of the year?

 

[srgalahad]

More than many of you want to know :

By FAA rule "Night" starts 1 hour after sunset (not last light), and ends 1 hour before sunrise.

Wellllll, not really...

According to the CFR (Title 14, Part 1.1 definitions) :"Night means the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the Air Almanac, converted to local time."

"Civil Twilight" is the time when the center of the sun's disk is 6.5* below the horizon.

So now we grab the Air Almanac - oh wait, it's only available (for US pilots) by purchase from the government. However, one has been posted (unofficially) at :
[h=1]NavList: A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
[/h]http://fer3.com/arc/m2.aspx/Air-Almanac-2020-full-pdf-now-available-FrankReed-dec-2019-g46422

If you download it, prepare for a headache. It includes a huge amount of data as it provides info for use in celestial nav. However, the pertinent data for pilots can be found way down near the bottom -Pages 871-886 (of 909 pages) where there is a set of tables for sunrise/sunset and Morning/Evening Civil Twilight and by Latitude (@ Sea Level). Oh, and you should be correcting for elevation as well. The tables only show 2-5* increments and~3-day intervals so interpolation is required. So, to be accurate, this is how you find whether it is "day" or "night".

Thank goodness, common practice is to use the times based on take-off and landing because it should be apparent that as you climb, the times will all change - and you could, theoretically takeoff at night, climb back into day and then have night arrive again

Also, different jurisdictions have rules that vary in wording and complexity. For most, the (sometimes legal) rule of thumb was 30 min after sunset to 30 minutes before sunrise. That's a rough average but "close enough for government work". As far as I can fathom, that general rule is no longer part of the CFR so you might have to argue with a FAA inspector.

Now to MSFS (or FS9/FSX for that matter) - all that is pretty convoluted and data-heavy. The sim does hold enough data to determine sunrise and sunset (but most accurate only at the moment the data is built in and 'slips' with each passing year.) MSFS may use more up-to-date data as part of the weather info downloaded with each use. However, I doubt the Logbook function would ever be robust enough to be anywhere near that accurate so they just grab something like sunrise/sunset, use the +/- 30 minute average, but I have doubts about how precise the Logbook would try to be for every user and location.

Also, with all the variances of Standard vs Daylight Saving time, I'd bet they are only sorta close (and makes a good case for, like real-world aviation, using UTC). As for that, it's easy enough to set up a second clock in W10 to show UTC.

 

[Tom Clayton]

You can also get twilight data here:
https://www.timeanddate.com/astronomy/civil-twilight.html

 

[P51FAN]

More than many of you want to know : Wellllll, not really... According to the CFR (Title 14, Part 1.1 definitions) :"Night means the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the Air Almanac, converted to local time." "Civil Twilight" is the time when the center of the sun's disk is 6.5* below the horizon. So now we grab the Air Almanac - oh wait, it's only available (for US pilots) by purchase from the government. However, one has been posted (unofficially) at : [h=1]NavList: A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding [/h]http://fer3.com/arc/m2.aspx/Air-Almanac-2020-full-pdf-now-available-FrankReed-dec-2019-g46422 If you download it, prepare for a headache. It includes a huge amount of data as it provides info for use in celestial nav. However, the pertinent data for pilots can be found way down near the bottom -Pages 871-886 (of 909 pages) where there is a set of tables for sunrise/sunset and Morning/Evening Civil Twilight and by Latitude (@ Sea Level). Oh, and you should be correcting for elevation as well. The tables only show 2-5* increments and~3-day intervals so interpolation is required. So, to be accurate, this is how you find whether it is "day" or "night". Thank goodness, common practice is to use the times based on take-off and landing because it should be apparent that as you climb, the times will all change - and you could, theoretically takeoff at night, climb back into day and then have night arrive again Also, different jurisdictions have rules that vary in wording and complexity. For most, the (sometimes legal) rule of thumb was 30 min after sunset to 30 minutes before sunrise. That's a rough average but "close enough for government work". As far as I can fathom, that general rule is no longer part of the CFR so you might have to argue with a FAA inspector. Now to MSFS (or FS9/FSX for that matter) - all that is pretty convoluted and data-heavy. The sim does hold enough data to determine sunrise and sunset (but most accurate only at the moment the data is built in and 'slips' with each passing year.) MSFS may use more up-to-date data as part of the weather info downloaded with each use. However, I doubt the Logbook function would ever be robust enough to be anywhere near that accurate so they just grab something like sunrise/sunset, use the +/- 30 minute average, but I have doubts about how precise the Logbook would try to be for every user and location. Also, with all the variances of Standard vs Daylight Saving time, I'd bet they are only sorta close (and makes a good case for, like real-world aviation, using UTC). As for that, it's easy enough to set up a second clock in W10 to show UTC.

And if you weren't confused enough before, add in the FAA's 3 different definitions of night. Sunset to sunrise for position/anticollision lights, civil twilight for logging night time, and 1 hour after sunset to 1 hour before sunrise for night currency.