Automatic Night Calculation


Well-known member
Jul 21, 2003
Hi all,

This is a very neat logook. I just picked it up and am very impressed.

One item I think would be great is an automatic night time determination based on Almanac data available from the US Gov't for free (although I don't know where).

Basically it's a text almanac that shows the sunrise and sunset for everyday of the year.

If you could make that importable into the logbook and have a function that automatically determines the night times based on OUT/IN times, that would be a very cool feature.

It has been a while since I have checked in here so I know this is a late add on comment...but I would have to agree that the automatic night calculation would be very handy in my application. I fly about 1500 hours a year and for the most part I take off and land at the same time every day and to have the logbook keep track of night and day would be very handy.
Here's the link to the Naval Observatory almanac generator. You could just add years from this as text files for the night lookup in LBP.

Anyway, I still think it would be VERY handy. If you have any amount of computed night time, it could even make the landing default to night or something too as an option.

I disagree on this subject. Different countries have different rules on when it is night. Also it will calculate night time in odd numbers. I log per 5 min. increments. Using a auto calculation, could make my flight a 1 min. night and 2:34 day... this is useless to me...


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I also have problems with this as different rules require different requirements for when to log night. Military may be 30 minutes off of civilian night requirements based on when they start logging night, etc. Something that will be looked into, but the more you tie the program to automation, the more you may cause problems for others. I'll see if a happy medium, if this is included, for user configuration, as always.

Maybe there could be a csutomizable section under "Automatic Night Calculations" that include civilian, military or custom. You could also just not use that feature as well. Custom could be where you'd select things like:
  • increments
  • definition of night
  • whether or not to log the landing as night if there is night time
  • Anything else people can use.

I agree about delving into too much automation, but the great thing about this type of feature is that night is the one thing that always requires pilots to look up since it changesevery day. You don't have to use the feature if you don't want to and it would help those who use it be more accurate with night logging and it would help simplify the night logging process.

Thanks for listening.

Neal -

I agree with you that there are too many 'definitions' of night exists to make this very feasible (of course it is probably 'possible', but may be too cumbersome).

As we recall, there are different definitions of the term night depending on its application, in addition to that recited above:

a) Civil twilight (i.e. night) affects logging of flight time (61.51) (FWIW, pilot training and certification (several sections of Part 61), Fuel requirements (91.151), VFR weather minimums (91.155) and aircraft instrument requirements (91.205)).

b) One hour before/after sunset/sunrise affects on when you can take passengers and log night takeoffs and landings for currency (61.57)

Regarding this issue of auto calculation of night times here is possibly a solution, use the option of an ON/OFF button selection for the use of night time calculation then when it inserts the calculated time, if you agree with it then continue entering the other details, if not then you should be able to change the times it calculated.

im sure this will be a feature that all will be happy with (i hope)

Again great program and great work with the forums.

Awaiting ver 2.0 ( this is more excitingthan waiting for a new Star Trek movie)

cheers from the other side of the world

Follow up- Night calculation program

Hi guys,

I started this thread and have finally gotten around to writing a night time calculator for my own CSV files that go into LBP. It works off of the equations from NOAA for civil times and FAR definitions of night and night landings for currency. It's in .NET and I'd be happy to show anyone and would love to get some feedback on it. I'd also like to see it considered for a future release of LBP as it seems simple enough once the user defines some parameters.

The calculation needs lat/lon (which I get from the embedded DAFIF files for the US airports in my little program) and times. It saves a user file with timezone data in it for use in DST issues in the US.

Anyway, I just wanted to see if anyone is interested in helping me get my program more user friendly for LBP users, and if the LBP folks had any interest in using some of what I've figured out for the LBP program at some point. Feel free to email me at if you're at all interested. It's free and I'm only interested in ensuring accuracy and ease of calculation for folks.

Doh! I was doing that at the same time. There's two threads with that download on the other forum. Would you mind removing one of them? Thanks Neal. That was lightning fast!