<?php

function sunIsUp(\DateTime $when, $lat, $lon): bool
{
    $whenTimestamp = $when->getTimestamp();

    [$sunriseTimestamp, $sunsetTimestamp] = array_map(function ($f) use ($whenTimestamp, $lat, $lon) {
        return $f($whenTimestamp, SUNFUNCS_RET_TIMESTAMP, $lat, $lon);
    }, ['date_sunrise', 'date_sunset']);

    return ($whenTimestamp > $sunriseTimestamp) && ($whenTimestamp < $sunsetTimestamp);
}