Open eriktorbjorn opened 4 years ago
I'm being very pedantic here, but the sunset times (at least - I haven't paid attention to the sunrise times) are unrealistic for the approximate latitude of Rockvil at the stated times of year - they're too late in January and February and too early in April, May, and June (even if we suppose that there is no Daylight Saving Time in the future, although doing so makes April closer). March is the closest, although still a little bit early.
I am so happy when I see Infocom bug notifications like this. Warms my heart in this Australian winter. 😄
Unlike "WAIT FOR DUSK", sunrise/sunset times probably work as designed though. As noted above, there are comments in the code that indicate that dawn is at "7:35am in January, 5:55am in June" and that dusk is at "5:08pm in January, 6:48pm in June". Anything between is just interpolated.
So I would be reluctant to change anything else around that.
Probably it shouldn't be changed, no, I just found it interesting to note that the times they picked aren't really correct for the locale.
The details for when the sun rises and sets can be found in
I-SUNRISE-SUNSET
, but the short version is that in January dusk begins at 5:28pm. Each month after that it starts 20 minutes later, i.e. 5:48pm in February, 6:08pm in March, etc.For instance, here's June 5th 2051. It should happen at or just after 6:48pm:
Eh. Close enough.
But here's how
V-WAIT-UNTIL
calculates the time for "WAIT UNTIL DUSK":So in January it's 5:08pm, but then it starts 20 minutes earlier for each subsequent month. Let's try it for the same date:
It should presumably be
<+ 1028 <- <* ,SMONTH 20> 20>>
instead.