diff --git a/haruhi_dl/extractor/extractors.py b/haruhi_dl/extractor/extractors.py
index 1c7fa90eb..b6d3a6c82 100644
--- a/haruhi_dl/extractor/extractors.py
+++ b/haruhi_dl/extractor/extractors.py
@@ -1107,6 +1107,7 @@ from .scte import (
     SCTECourseIE,
 )
 from .seeker import SeekerIE
+from .sejmpl import SejmPlArchivalIE
 from .senateisvp import SenateISVPIE
 from .sendtonews import SendtoNewsIE
 from .servus import ServusIE
diff --git a/haruhi_dl/extractor/sejmpl.py b/haruhi_dl/extractor/sejmpl.py
new file mode 100644
index 000000000..31e3d766c
--- /dev/null
+++ b/haruhi_dl/extractor/sejmpl.py
@@ -0,0 +1,61 @@
+# coding: utf-8
+
+from .common import InfoExtractor
+from ..utils import (
+    clean_html,
+)
+
+import datetime
+import re
+
+
+class SejmPlArchivalIE(InfoExtractor):
+    _VALID_URL = r'https?://(?:www\.)?sejm\.gov\.pl/Sejm(?P<term>\d+)\.nsf/transmisje_arch\.xsp(?:\?(?:[^&\s]+(?:&[^&\s]+)*)?)?(?:#|unid=)(?P<id>[\dA-F]+)'
+    IE_NAME = 'sejm.pl:archival'
+
+    def _real_extract(self, url):
+        mobj = re.match(self._VALID_URL, url)
+        term, video_id = mobj.group('term', 'id')
+        data = self._download_json(
+            'https://www.sejm.gov.pl/Sejm%s.nsf/transmisje_arch.xsp/json/%s' % (term, video_id),
+            video_id, headers={
+                'Referer': 'https://www.sejm.gov.pl/Sejm%s.nsf/transmisje_arch.xsp' % (term),
+            })
+        params = data['params']
+
+        def iso_date_to_wtf_atende_wants(date):
+            date = datetime.datetime.fromisoformat(date)
+            # atende uses timestamp but since 2001 instead of 1970
+            date = date.replace(year=date.year - 31)
+            # also it's in milliseconds
+            return int(date.timestamp() * 1000)
+
+        start_time = iso_date_to_wtf_atende_wants(params['start'])
+        stop_time = iso_date_to_wtf_atende_wants(params['stop'])
+        time_query = 'startTime=%d&stopTime=%d' % (start_time, stop_time)
+
+        file = params['file'].replace('http:', 'https:')
+        formats = [{
+            'url': file + '?' + time_query,
+            'ext': 'flv',
+            'format_id': 'direct-0',
+            'preference': -1,   # VERY slow to download (~200 KiB/s, compared to ~10-15 MiB/s by DASH/HLS)
+        }]
+        formats.extend(self._extract_mpd_formats(
+            file.replace('/nvr/', '/livedash/') + '?indexMode=true&' + time_query,
+            video_id, mpd_id='dash'))
+        formats.extend(self._extract_m3u8_formats(
+            file.replace('/nvr/', '/livehls/') + '/playlist.m3u8?indexMode=true&' + time_query,
+            video_id, m3u8_id='hls'))
+
+        self._sort_formats(formats)
+
+        duration = stop_time - start_time
+
+        return {
+            'formats': formats,
+            'id': video_id,
+            'title': data['title'],
+            'description': clean_html(data['desc']),
+            'duration': duration,
+        }