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kevinboone / solunar_cmdline

Command-line utility for displaying solar and lunar ephemera
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Incorrect seasons/solstices for southern hemisphere #5

Open cryptarch opened 5 years ago

cryptarch commented 5 years ago

Hi,

Thanks for your work on this program, it is very nice and useful.

I did just notice a bug. It seems like the seasons given always assume northern hemisphere. Let me show you what I mean:

$ solunar -c melbourne --days
Selected city Australia/Melbourne
Using location 37:49S,144:58E
Date/time Fri Dec 21 16:55:49 2018 local

Tuesday 13 February 2018   Shrove Tuesday
Wednesday 14 February 2018 Ash Wednesday
Sunday 11 March 2018       Mothering Sunday
Wednesday 21 March 2018    Vernal equinox (03:16)
Sunday 25 March 2018       Palm Sunday
Thursday 29 March 2018     Maundy Thursday
Friday 30 March 2018       Good Friday
Sunday  1 April 2018       Easter Sunday
Monday  2 April 2018       Easter Monday
Sunday 20 May 2018         Whitsun/Pentecost
Thursday 21 June 2018      Summer solstice (20:08)
Sunday 23 September 2018   Autumnal equinox (11:55)
Saturday 22 December 2018  Winter solstice (09:23)

Notice how it says our summer solstice is in June and our winter solstice is in December.

Hopefully this isn't too hard to fix. I might even try to fix it myself, but maybe you can do it faster :)

kevinboone commented 5 years ago

I've changed the solstices to show "winter" and "summer" according to the hemisphere. I'm assuming that the designations need to be changed for any location south of the equator -- please let me know if that isn't your understanding. I've pushed a new version for testing.

I'm not entirely sure what to do about "vernal equinox", etc., however. I believe that the term is used (at least by English speakers") all over the Northern Hemisphere to refer to an event that happens in March. However, I believe that some places in the Southern Hemisphere use "vernal" to refer to the event in September (which makes more logical sense) while some refer to march, as we Northerners do. So, while it's easy to change the program if the rules are simple, I'm not sure they are in this case.

Comments welcome.

cryptarch commented 5 years ago

Thanks! I just checked out the latest commit, the solstices look correct now.

I didn't check the equinox naming, but now that you mention it I think those too should be reversed. Certainly "Autumnal Equinox" should refer to the event in March, for us. If it's not too much trouble could you please reverse the equinoxes for southern hemisphere as well?