Wrong date in European timezone results

[ottopic]

Hello @gregseth ,
thank you for your great work.
I'm testing your script but I have strange problem.

If I try to calculate sunTimes with:

datetime : 2019-02-09 00:01:00
latitude: 43.7102466075706
longitude: 11.2609452326665

in results I find the day before 2019-02-08

$sun_info:
Array
(
    [solarNoon] => DateTime Object
        (
            [date] => 2019-02-08 12:30:28.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [nadir] => DateTime Object
        (
            [date] => 2019-02-08 00:30:28.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [sunrise] => DateTime Object
        (
            [date] => 2019-02-08 07:25:21.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [sunset] => DateTime Object
        (
            [date] => 2019-02-08 17:35:35.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [sunriseEnd] => DateTime Object
        (
            [date] => 2019-02-08 07:28:30.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [sunsetStart] => DateTime Object
        (
            [date] => 2019-02-08 17:32:26.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [dawn] => DateTime Object
        (
            [date] => 2019-02-08 06:55:19.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [dusk] => DateTime Object
        (
            [date] => 2019-02-08 18:05:37.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [nauticalDawn] => DateTime Object
        (
            [date] => 2019-02-08 06:21:19.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [nauticalDusk] => DateTime Object
        (
            [date] => 2019-02-08 18:39:37.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [nightEnd] => DateTime Object
        (
            [date] => 2019-02-08 05:47:53.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [night] => DateTime Object
        (
            [date] => 2019-02-08 19:13:04.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [goldenHourEnd] => DateTime Object
        (
            [date] => 2019-02-08 08:06:44.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

    [goldenHour] => DateTime Object
        (
            [date] => 2019-02-08 16:54:12.000000
            [timezone_type] => 3
            [timezone] => Europe/Rome
        )

)

I tried to edit your script passing right timezone to "fromJulian" function but never change. Can you help me?

[ottopic]

@gregseth using UTC date time and converting it in current timezone the result it seems to works but only in my current European timezone, if I try with U.S.A latitude and longitude it returns wrong day.

[ottopic]

This is the workaround I have found to calculate correct date time, but I don't think it's a good job, someone can help me?

$DateTimeZone = new DateTimeZone($timeZone->timeZoneId);
$DateTimeZoneUTC = new DateTimeZone("UTC");

if(strpos($timeZone->timeZoneId, "Europe") !== false) $DateTimeZone = $DateTimeZoneUTC;

$newSunData = new AurorasLive\SunCalc(new DateTime($date, $DateTimeZone), $lat, $lng);

[su1736]

If I try to calculate sunTimes with:

datetime : 2019-02-09 00:01:00
latitude: 43.7102466075706
longitude: 11.2609452326665

in results I find the day before 2019-02-08

I also faced with this problem. I don't found right fix or workaround for this yet.

[pixlmint]

I have encountered this same issue and found that modifying this line to read $d = toDays($this->date) + 0.5; fixes the issue

If you look at the toJulian function, there 0.5 gets subtracted from the result, I believe that means it removes half a day from the time, and if you're using 00:00 as time from which to calculate the sun/moon times, then remove half a day, the previous day will be selected.

This seems to be working for me, but certainly needs more testing.

Comparing the results this gives me to what timeanddate is telling me, the sun times only have a variation of +/- 5 minutes. Though you cannot add the 0.5 to the moontimes algorithm, as that will mess things up.

This was tested at 5 different coordinates with 20 random dates

[PendalF89]

@pixlmint

I have encountered this same issue and found that modifying this line to read $d = toDays($this->date) + 0.5; fixes the issue

Unfortunately, no. Please, check this comment: mourner/suncalc#107 (comment)

Here is my implementation on PHP:

function toJulian($date): float
{
    $month = $date->format('m');
    $day = $date->format('d');
    $year = $date->format('Y');

    $gregorian = !($year < 1583);

    if ($month == 1 || $month == 2) {
        $year -= 1;
        $month += 12;
    }

    $a = floor($year / 100);

    if ($gregorian) {
        $b = 2 - $a + floor($a / 4);
    } else {
        $b = 0.0;
    }

    $jd = floor(365.25 * ($year + 4716))
        + floor(30.6001 * ($month + 1))
        + $day + $b - 1524.5;

    return $jd + 0.5;
}