In date_sun_info () what is Transit

Question

I understand the meaning of Sun Transit as the time it takes for the sun to go from sunrise to sunset, however the date_sun_info () transit seems to return the midpoint on the day when the sun is exactly between sunrise and sunset.

$sun_info = date_sun_info(strtotime("2006-12-12"), 31.7667, 35.2333); foreach ($sun_info as $key => $val) { echo "$key: " . date("H:i:s", $val) . "\n"; } 

The above example outputs:

sunrise: 5:52:11
sunset: 15:41:21
transit: 10:46:46
civil_twilight_begin: 05:24:08
civil_twilight_end: 16:09:24
nautical_twilight_begin: 04:52:25
nautical_twilight_end: 16:41:06
astronomical_twilight_begin: 04:21:32
astronomical_twilight_end: 17:12:00

Answer 1

Transit is the time when the sun passes over the meridian observer. Thus, at noon the sundial is at the longitude that you are in. The hours of noon and sunny noon are often very different, and I suspect that the time is given UTC, although this is an assumption, as it is not explained in the manual, and I would expect this to give a result closer to 12:00, although I did not have time correctly check the calculation.

Perhaps the person who wrote this function did not understand the term "transit" in the same way as the person who wrote the functions date_sunrise () and date_sunset () did not understand the term "zenith" .