Sunrise time calculation error

[tz850]

version 3.2

I used latitude 39.3528 and longitude 106.7333 to calculate the sunrise and sunset times for the whole year of 2015, starting on February 3, 2015, the calculated sunrise time was later than the sunset time, and this was the case until December 7, 2015.

my code:

lat_station_val = 39.35277777777778
lon_station_val = 106.73333333333333

location_staion9 = LocationInfo('shizuishan','china','Asia/Shanghai',lat_station_val,lon_station_val)

data_file = open("result.csv", 'w') 
data_file.write("date,sunrise,sunset\n")

start_date = date(2015, 1, 1)
for i in range(0,365):
    delta=timedelta(days=i)
    cal_date = start_date + delta

    s = sun(location_staion9.observer, date=cal_date)
    utc_sunrise = s["sunrise"]
    utc_sunset = s["sunset"]

    data_file.write("{},{},{}\n".format(cal_date.strftime('%Y-%m-%d'), utc_sunrise.strftime('%Y-%m-%d %H:%M:%S'), utc_sunset.strftime('%Y-%m-%d %H:%M:%S')))

the result:

2015-01-28,2015-01-28 00:04:28,2015-01-28 10:07:44
2015-01-29,2015-01-29 00:03:41,2015-01-29 10:08:55
2015-01-30,2015-01-30 00:02:52,2015-01-30 10:10:06
2015-01-31,2015-01-31 00:02:01,2015-01-31 10:11:16
2015-02-01,2015-02-01 00:01:08,2015-02-01 10:12:27
2015-02-02,2015-02-02 00:00:14,2015-02-02 10:13:38
**2015-02-03,2015-02-03 23:58:20,2015-02-03 10:14:49**
2015-02-04,2015-02-04 23:57:21,2015-02-04 10:16:00
2015-02-05,2015-02-05 23:56:20,2015-02-05 10:17:11
2015-02-06,2015-02-06 23:55:18,2015-02-06 10:18:21
2015-02-07,2015-02-07 23:54:14,2015-02-07 10:19:32
2015-02-08,2015-02-08 23:53:09,2015-02-08 10:20:42
2015-02-09,2015-02-09 23:52:02,2015-02-09 10:21:53
2015-02-10,2015-02-10 23:50:54,2015-02-10 10:23:03
2015-02-11,2015-02-11 23:49:45,2015-02-11 10:24:13