Fix date_sunrise() with partial-hour UTC offset

See GH-19633

Author: iluuu1994

ext/date/php_date.c

@@ -5328,7 +5328,7 @@ static void php_do_date_sunrise_sunset(INTERNAL_FUNCTION_PARAMETERS, bool calc_s
 	t->zone_type = TIMELIB_ZONETYPE_ID;
 
 	if (gmt_offset_is_null) {
-		gmt_offset = timelib_get_current_offset(t) / 3600;
+		gmt_offset = timelib_get_current_offset(t) / 3600.0;
 	}
 
 	timelib_unixtime2local(t, time);

ext/date/tests/sunfuncts_partial_hour_utc_offset.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Incorrect timezone detection in date_sunrise() for partial-hour UTC offsets
+--FILE--
+<?php
+date_default_timezone_set('Asia/Kolkata');
+$timestamp = mktime(0, 0, 0, 2, 9, 2025);
+$longitude = 22.57;
+$latitude = 88.36;
+
+echo @date_sunrise($timestamp, SUNFUNCS_RET_STRING, $longitude, $latitude), "\n";
+
+$dt = new DateTime();
+$dt->setTimestamp(date_sun_info($timestamp, $longitude, $latitude)['sunrise']);
+echo $dt->format('H:i'), "\n";
+?>
+--EXPECT--
+06:10
+06:11