diff --git a/docs/uri-scheme-browse-origin.rst b/docs/uri-scheme-browse-origin.rst
--- a/docs/uri-scheme-browse-origin.rst
+++ b/docs/uri-scheme-browse-origin.rst
@@ -91,8 +91,8 @@
         to retrieve the root directory
     :query string revision: specify the origin revision, identified by the hexadecimal
         representation of its **sha1_git** value, from which to retrieve the root directory
-    :query string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :query string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :query int visit_id: specify a visit id to retrieve the directory from instead
         of using the latest full visit by default
     :statuscode 200: no error
@@ -109,9 +109,7 @@
         :swh_web_browse:`origin/directory/?origin_url=https://github.com/python/cpython`
         :swh_web_browse:`origin/directory/?origin_url=https://github.com/python/cpython&path=Python`
         :swh_web_browse:`origin/directory/?origin_url=https://github.com/python/cpython&branch=refs/heads/2.7`
-        :swh_web_browse:`origin/directory/?origin_url=https://github.com/torvalds/linux&timestamp=1493926809`
         :swh_web_browse:`origin/directory/?origin_url=https://github.com/torvalds/linux&path=net/ethernet&timestamp=2016-09-14T10:36:21Z`
-        :swh_web_browse:`origin/directory/?origin_url=https://github.com/python/cpython&timestamp=1474620651`
         :swh_web_browse:`origin/directory/?origin_url=https://github.com/python/cpython&path=Python&timestamp=2017-05-05`
         :swh_web_browse:`origin/directory/?origin_url=https://github.com/python/cpython&branch=refs/heads/2.7&timestamp=2015-08`
 
@@ -192,8 +190,8 @@
     content can also be specified by using the branch query parameter.
 
     :param string origin_url: the url of the origin (e.g. https://github.com/(user)/(repo)/)
-    :param string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :param string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :param path: optional parameter used to specify the path of a directory
         reachable from the origin root one
     :type path: string
@@ -259,8 +257,8 @@
         to retrieve the content
     :query string revision: specify the origin revision, identified by the hexadecimal
         representation of its **sha1_git** value, from which to retrieve the content
-    :query string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :query string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :query int visit_id: specify a visit id to retrieve the content from instead
         of using the latest full visit by default
     :statuscode 200: no error
@@ -275,9 +273,7 @@
         :swh_web_browse:`origin/content/?origin_url=https://github.com/git/git?path=git.c`
         :swh_web_browse:`origin/content/?origin_url=https://github.com/mozilla/gecko-dev&path=js/src/json.cpp`
         :swh_web_browse:`origin/content/?origin_url=https://github.com/git/git?path=git.c&branch=refs/heads/next`
-        :swh_web_browse:`origin/content/?origin_url=https://github.com/git/git&path=git.c&timestamp=1473933564`
         :swh_web_browse:`origin/content/?origin_url=https://github.com/git/git&path=git.c&timestamp=2016-05-05T00:0:00+00:00Z`
-        :swh_web_browse:`origin/content/?origin_url=https://github.com/mozilla/gecko-dev&path=js/src/json.cpp&timestamp=1490126182`
         :swh_web_browse:`origin/content/?origin_url=https://github.com/mozilla/gecko-dev&path=js/src/json.cpp&timestamp=2017-03-21#L904-L931`
         :swh_web_browse:`origin/content/?origin_url=https://github.com/git/git&path=git.c&branch=refs/heads/next&timestamp=2017-09-15`
 
@@ -320,8 +316,8 @@
         to retrieve the content
     :query string revision: specify the origin revision, identified by the hexadecimal
         representation of its **sha1_git** value, from which to retrieve the content
-    :query string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :query string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :query int visit_id: specify a visit id to retrieve the content from instead
         of using the latest full visit by default
     :statuscode 200: no error
@@ -336,9 +332,7 @@
         :swh_web_browse:`origin/https://github.com/git/git/content/?path=git.c`
         :swh_web_browse:`origin/https://github.com/mozilla/gecko-dev/content/?path=js/src/json.cpp`
         :swh_web_browse:`origin/https://github.com/git/git/content/?path=git.c&branch=refs/heads/next`
-        :swh_web_browse:`origin/https://github.com/git/git/content/?path=git.c&timestamp=1473933564`
         :swh_web_browse:`origin/https://github.com/git/git/content/?path=git.c&timestamp=2016-05-05T00:0:00+00:00Z`
-        :swh_web_browse:`origin/https://github.com/mozilla/gecko-dev/content?path=js/src/json.cpp&timestamp=1490126182`
         :swh_web_browse:`origin/https://github.com/mozilla/gecko-dev/content?path=js/src/json.cpp&timestamp=2017-03-21#L904-L931`
         :swh_web_browse:`origin/https://github.com/git/git/content/git.c/?branch=refs/heads/next&timestamp=2017-09-15`
 
@@ -428,8 +422,8 @@
     can also be specified by using the branch query parameter.
 
     :param string origin_url: the url of the origin (e.g. https://github.com/(user)/(repo)/)
-    :param string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :param string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :param string path: path of a content reachable from the origin root directory
     :query string branch: specify the origin branch name from which
         to retrieve the content
@@ -448,9 +442,7 @@
 
     .. parsed-literal::
 
-        :swh_web_browse:`origin/https://github.com/git/git/visit/1473933564/content/git.c/`
         :swh_web_browse:`origin/https://github.com/git/git/visit/2016-05-05T00:0:00+00:00Z/content/git.c/`
-        :swh_web_browse:`origin/https://github.com/mozilla/gecko-dev/visit/1490126182/content/js/src/json.cpp/`
         :swh_web_browse:`origin/https://github.com/mozilla/gecko-dev/visit/2017-03-21/content/js/src/json.cpp/#L904-L931`
         :swh_web_browse:`origin/https://github.com/git/git/visit/2017-09-15/content/git.c/?branch=refs/heads/next`
 
@@ -502,8 +494,8 @@
         to retrieve the commit log
     :query string revision: specify the origin revision, identified by the hexadecimal
         representation of its **sha1_git** value, from which to retrieve the commit log
-    :query string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :query string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :query int visit_id: specify a visit id to retrieve the history log from instead
         of using the latest visit by default
     :statuscode 200: no error
@@ -571,8 +563,8 @@
         to retrieve the commit log
     :query string revision: specify the origin revision, identified by the hexadecimal
         representation of its **sha1_git** value, from which to retrieve the commit log
-    :query string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :query string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :query int visit_id: specify a visit id to retrieve the history log from instead
         of using the latest visit by default
     :statuscode 200: no error
@@ -585,9 +577,7 @@
         :swh_web_browse:`origin/https://github.com/videolan/vlc/log/`
         :swh_web_browse:`origin/https://github.com/Kitware/CMake/log/`
         :swh_web_browse:`origin/https://github.com/Kitware/CMake/log/?branch=refs/heads/release`
-        :swh_web_browse:`origin/https://github.com/videolan/vlc/log/?visit=1459651262`
         :swh_web_browse:`origin/https://github.com/Kitware/CMake/log/?timestamp=2016-04-01`
-        :swh_web_browse:`origin/https://github.com/Kitware/CMake/log/?branch=refs/heads/release&timestamp=1438116814`
         :swh_web_browse:`origin/https://github.com/Kitware/CMake/log/?branch=refs/heads/release&timestamp=2017-05-05T03:14:23Z`
 
 
@@ -626,8 +616,8 @@
     can also be specified by using the branch query parameter.
 
     :param string origin_url: the url of the origin (e.g. https://github.com/(user)/(repo)/)
-    :param string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :param string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :query int per_page: the number of log entries to display per page
         (default is 20, max is 50)
     :query string branch: specify the origin branch name from which
@@ -645,9 +635,7 @@
 
     .. parsed-literal::
 
-        :swh_web_browse:`origin/https://github.com/videolan/vlc/visit/1459651262/log/`
         :swh_web_browse:`origin/https://github.com/Kitware/CMake/visit/2016-04-01/log/`
-        :swh_web_browse:`origin/https://github.com/Kitware/CMake/visit/1438116814/log/?branch=refs/heads/release`
         :swh_web_browse:`origin/https://github.com/Kitware/CMake/visit/2017-05-05T03:14:23Z/log/?branch=refs/heads/release`
 
 Origin branches
@@ -670,8 +658,8 @@
 
     :query string origin_url: mandatory parameter providing the url of the origin
         (e.g. https://github.com/(user)/(repo))
-    :query string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :query string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :statuscode 200: no error
     :statuscode 400: no origin url has been provided as parameter
     :statuscode 404: requested origin can not be found in the archive
@@ -706,8 +694,8 @@
     That list of branches is paginated, each page displaying a maximum of 100 branches.
 
     :param string origin_url: the url of the origin (e.g. https://github.com/(user)/(repo)/)
-    :query string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :query string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :statuscode 200: no error
     :statuscode 404: requested origin can not be found in the archive
 
@@ -741,8 +729,8 @@
     That list of branches is paginated, each page displaying a maximum of 100 branches.
 
     :param string origin_url: the url of the origin (e.g. https://github.com/(user)/(repo)/)
-    :param string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :param string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :statuscode 200: no error
     :statuscode 404: requested origin can not be found in the archive
 
@@ -773,8 +761,8 @@
 
     :query string origin_url: mandatory parameter providing the url of the origin
         (e.g. https://github.com/(user)/(repo))
-    :query string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :query string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :statuscode 200: no error
     :statuscode 400: no origin url has been provided as parameter
     :statuscode 404: requested origin can not be found in the archive
@@ -809,8 +797,8 @@
     That list of releases is paginated, each page displaying a maximum of 100 releases.
 
     :param string origin_url: the url of the origin (e.g. https://github.com/(user)/(repo)/)
-    :query string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :query string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :statuscode 200: no error
     :statuscode 404: requested origin can not be found in the archive
 
@@ -844,8 +832,8 @@
     That list of releases is paginated, each page displaying a maximum of 100 releases.
 
     :param string origin_url: the url of the origin (e.g. https://github.com/(user)/(repo)/)
-    :param string timestamp: a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
+    :param string timestamp: an ISO 8601 datetime string to parse in order to find the
+      closest visit.
     :statuscode 200: no error
     :statuscode 404: requested origin can not be found in the archive
 
@@ -858,4 +846,3 @@
 
 
 .. _highlightjs: https://highlightjs.org/
-.. _dateutil.parser.parse: http://dateutil.readthedocs.io/en/stable/parser.html
diff --git a/docs/uri-scheme-browse-revision.rst b/docs/uri-scheme-browse-revision.rst
--- a/docs/uri-scheme-browse-revision.rst
+++ b/docs/uri-scheme-browse-revision.rst
@@ -20,13 +20,11 @@
          identifier of a revision
     :query string origin_url: used internally to associate an origin url
         (e.g. https://github.com/user/repo) to the revision
-    :query string timestamp: used internally to associate an origin visit to the
-        revision, must be a date string (any format parsable by `dateutil.parser.parse`_)
-        or Unix timestamp to parse in order to find the closest visit.
-    :query int visit_id: used internally to specify a visit id instead of
+    :query string timestamp: an ISO 8601 datetime string to parse in order to find the
+        closest visit.
+    :query int visit_id: specify a visit id instead of
         using the provided timestamp
-    :query string path: used internally when navigating in the source tree
-        associated to the revision
+    :query string path: optional relative path from the revision root directory
     :statuscode 200: no error
     :statuscode 404: requested revision can not be found in the archive
 
@@ -37,8 +35,6 @@
         :swh_web_browse:`revision/f1b94134a4b879bc55c3dacdb496690c8ebdc03f/`
         :swh_web_browse:`revision/d1aa2b3f607b35dc5dbf613b2334b6d243ec2bda/`
 
-    .. _dateutil.parser.parse: http://dateutil.readthedocs.io/en/stable/parser.html
-
 .. http:get:: /browse/revision/(sha1_git)/log/
 
     HTML view that displays the list of revisions heading to
diff --git a/docs/uri-scheme-browse.rst b/docs/uri-scheme-browse.rst
--- a/docs/uri-scheme-browse.rst
+++ b/docs/uri-scheme-browse.rst
@@ -69,7 +69,6 @@
   principle of least surprise. At the very minimum it is possible to
   enter timestamps as:
 
-  - Unix epoch timestamp (see for instance the output of `date +%s`)
   - ISO 8601 timestamps (see for instance the output of `date -I`, `date -Is`)
   - YYYY[MM[DD[HH[MM[SS]]]]] ad-hoc format
   - YYYY[-MM[-DD[ HH:[MM:[SS:]]]]] ad-hoc format
diff --git a/mypy.ini b/mypy.ini
--- a/mypy.ini
+++ b/mypy.ini
@@ -21,6 +21,9 @@
 [mypy-htmlmin.*]
 ignore_missing_imports = True
 
+[mypy-iso8601.*]
+ignore_missing_imports = True
+
 [mypy-keycloak.*]
 ignore_missing_imports = True
 
diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,11 +10,11 @@
 django-webpack-loader
 docutils
 htmlmin
+iso8601
 lxml
 prometheus-client
 pybadges
 pygments
-python-dateutil
 python-keycloak >= 0.19.0
 python-magic >= 0.4.0
 python-memcached
diff --git a/swh/web/browse/snapshot_context.py b/swh/web/browse/snapshot_context.py
--- a/swh/web/browse/snapshot_context.py
+++ b/swh/web/browse/snapshot_context.py
@@ -7,7 +7,7 @@
 
 from collections import defaultdict
 from copy import copy
-from typing import Any, Dict, List, Optional, Union, Tuple
+from typing import Any, Dict, List, Optional, Tuple
 
 
 from django.core.cache import cache
@@ -348,7 +348,7 @@
 
 def get_origin_visit_snapshot(
     origin_info: OriginInfo,
-    visit_ts: Optional[Union[int, str]] = None,
+    visit_ts: Optional[str] = None,
     visit_id: Optional[int] = None,
     snapshot_id: Optional[str] = None,
 ) -> Tuple[List[SnapshotBranchInfo], List[SnapshotReleaseInfo]]:
@@ -372,7 +372,7 @@
 
     Args:
         origin_info: a dict filled with origin information
-        visit_ts: an ISO date string or Unix timestamp to parse
+        visit_ts: an ISO 8601 datetime string to parse
         visit_id: visit id for disambiguation in case several visits have
             the same timestamp
         snapshot_id: if provided, visit associated to the snapshot will be processed
diff --git a/swh/web/browse/views/origin.py b/swh/web/browse/views/origin.py
--- a/swh/web/browse/views/origin.py
+++ b/swh/web/browse/views/origin.py
@@ -18,7 +18,7 @@
 from swh.web.common import service
 from swh.web.common.exc import handle_view_exception, BadInputExc
 from swh.web.common.origin_visits import get_origin_visits
-from swh.web.common.utils import reverse, format_utc_iso_date, parse_timestamp
+from swh.web.common.utils import reverse, format_utc_iso_date, parse_iso8601_date_to_utc
 
 
 @browse_route(
@@ -255,7 +255,7 @@
         visit["url"] = reverse("browse-origin-directory", query_params=query_params,)
         if not snapshot:
             visit["snapshot"] = ""
-        visit["date"] = parse_timestamp(visit["date"]).timestamp()
+        visit["date"] = parse_iso8601_date_to_utc(visit["date"]).timestamp()
 
     heading = "Origin visits - %s" % origin_url
 
diff --git a/swh/web/common/origin_save.py b/swh/web/common/origin_save.py
--- a/swh/web/common/origin_save.py
+++ b/swh/web/common/origin_save.py
@@ -38,7 +38,7 @@
     SAVE_TASK_NOT_CREATED,
 )
 from swh.web.common.origin_visits import get_origin_visits
-from swh.web.common.utils import parse_timestamp, SWH_WEB_METRICS_REGISTRY
+from swh.web.common.utils import parse_iso8601_date_to_utc, SWH_WEB_METRICS_REGISTRY
 
 from swh.scheduler.utils import create_oneshot_task_dict
 
@@ -159,7 +159,7 @@
             origin = {"url": save_request.origin_url}
             origin_info = service.lookup_origin(origin)
             origin_visits = get_origin_visits(origin_info)
-            visit_dates = [parse_timestamp(v["date"]) for v in origin_visits]
+            visit_dates = [parse_iso8601_date_to_utc(v["date"]) for v in origin_visits]
             i = bisect_right(visit_dates, save_request.request_date)
             if i != len(visit_dates):
                 visit_date = visit_dates[i]
diff --git a/swh/web/common/origin_visits.py b/swh/web/common/origin_visits.py
--- a/swh/web/common/origin_visits.py
+++ b/swh/web/common/origin_visits.py
@@ -4,13 +4,13 @@
 # See top-level LICENSE file for more information
 
 import math
-from typing import List, Optional, Union
+from typing import List, Optional
 
 from django.core.cache import cache
 
 from swh.web.common.exc import NotFoundExc
 from swh.web.common.typing import OriginInfo, OriginVisitInfo
-from swh.web.common.utils import parse_timestamp
+from swh.web.common.utils import parse_iso8601_date_to_utc
 
 
 def get_origin_visits(origin_info: OriginInfo) -> List[OriginVisitInfo]:
@@ -71,7 +71,7 @@
                 last_visit += per_page
 
     def _visit_sort_key(visit):
-        ts = parse_timestamp(visit["date"]).timestamp()
+        ts = parse_iso8601_date_to_utc(visit["date"]).timestamp()
         return ts + (float(visit["visit"]) / 10e3)
 
     origin_visits = sorted(origin_visits, key=lambda v: _visit_sort_key(v))
@@ -83,7 +83,7 @@
 
 def get_origin_visit(
     origin_info: OriginInfo,
-    visit_ts: Optional[Union[int, str]] = None,
+    visit_ts: Optional[str] = None,
     visit_id: Optional[int] = None,
     snapshot_id: Optional[str] = None,
 ) -> OriginVisitInfo:
@@ -101,7 +101,7 @@
 
     Args:
         origin_info: a dict filled with origin information
-        visit_ts: an ISO date string or Unix timestamp to parse
+        visit_ts: an ISO 8601 datetime string to parse
         snapshot_id: a snapshot identifier
 
     Returns:
@@ -161,12 +161,12 @@
 
     if visit_ts:
 
-        target_visit_ts = math.floor(parse_timestamp(visit_ts).timestamp())
+        target_visit_ts = math.floor(parse_iso8601_date_to_utc(visit_ts).timestamp())
 
         # Find the visit with date closest to the target (in absolute value)
         (abs_time_delta, visit_idx) = min(
             (
-                (math.floor(parse_timestamp(visit["date"]).timestamp()), i)
+                (math.floor(parse_iso8601_date_to_utc(visit["date"]).timestamp()), i)
                 for (i, visit) in enumerate(visits)
             ),
             key=lambda ts_and_i: abs(ts_and_i[0] - target_visit_ts),
diff --git a/swh/web/common/utils.py b/swh/web/common/utils.py
--- a/swh/web/common/utils.py
+++ b/swh/web/common/utils.py
@@ -6,9 +6,6 @@
 import re
 
 from datetime import datetime, timezone
-from dateutil import parser as date_parser
-from dateutil import tz
-
 from typing import Optional, Dict, Any
 
 import docutils.parsers.rst
@@ -22,6 +19,8 @@
 from django.urls import reverse as django_reverse
 from django.http import QueryDict, HttpRequest
 
+from iso8601 import parse_date, ParseError
+
 from prometheus_client.registry import CollectorRegistry
 
 from rest_framework.authentication import SessionAuthentication
@@ -104,39 +103,32 @@
     Returns:
         datetime.datetime: datetime in UTC without timezone info
     """
-    if date.tzinfo:
-        return date.astimezone(tz.gettz("UTC")).replace(tzinfo=timezone.utc)
+    if date.tzinfo and date.tzinfo != timezone.utc:
+        return date.astimezone(tz=timezone.utc)
     else:
         return date
 
 
-def parse_timestamp(timestamp):
-    """Given a time or timestamp (as string), parse the result as UTC datetime.
+def parse_iso8601_date_to_utc(iso_date: str) -> datetime:
+    """Given an ISO 8601 datetime string, parse the result as UTC datetime.
 
     Returns:
-        datetime.datetime: a timezone-aware datetime representing the
-            parsed value or None if the parsing fails.
+        a timezone-aware datetime representing the parsed date
+
+    Raises:
+        swh.web.common.exc.BadInputExc: provided date does not respect ISO 8601 format
 
     Samples:
         - 2016-01-12
         - 2016-01-12T09:19:12+0100
-        - Today is January 1, 2047 at 8:21:00AM
-        - 1452591542
+        - 2007-01-14T20:34:22Z
 
     """
-    if not timestamp:
-        return None
-
     try:
-        date = date_parser.parse(timestamp, ignoretz=False, fuzzy=True)
+        date = parse_date(iso_date)
         return datetime_to_utc(date)
-    except Exception:
-        try:
-            return datetime.utcfromtimestamp(float(timestamp)).replace(
-                tzinfo=timezone.utc
-            )
-        except (ValueError, OverflowError) as e:
-            raise BadInputExc(e)
+    except ParseError as e:
+        raise BadInputExc(e)
 
 
 def shorten_path(path):
@@ -151,7 +143,7 @@
 
 
 def format_utc_iso_date(iso_date, fmt="%d %B %Y, %H:%M UTC"):
-    """Turns a string representation of an ISO 8601 date string
+    """Turns a string representation of an ISO 8601 datetime string
     to UTC and format it into a more human readable one.
 
     For instance, from the following input
@@ -169,7 +161,7 @@
     """
     if not iso_date:
         return iso_date
-    date = parse_timestamp(iso_date)
+    date = parse_iso8601_date_to_utc(iso_date)
     return date.strftime(fmt)
 
 
diff --git a/swh/web/tests/browse/views/test_origin.py b/swh/web/tests/browse/views/test_origin.py
--- a/swh/web/tests/browse/views/test_origin.py
+++ b/swh/web/tests/browse/views/test_origin.py
@@ -29,7 +29,7 @@
     reverse,
     gen_path_info,
     format_utc_iso_date,
-    parse_timestamp,
+    parse_iso8601_date_to_utc,
 )
 from swh.web.tests.data import get_content, random_sha1
 from swh.web.tests.django_asserts import assert_contains, assert_template_used
@@ -118,21 +118,6 @@
         timestamp=tdata["visit"]["date"],
     )
 
-    visit_unix_ts = parse_timestamp(tdata["visit"]["date"]).timestamp()
-    visit_unix_ts = int(visit_unix_ts)
-
-    _origin_content_view_test_helper(
-        client,
-        archive_data,
-        origin,
-        origin_visits[-1],
-        tdata["branches"],
-        tdata["releases"],
-        tdata["root_dir_sha1"],
-        tdata["content"],
-        timestamp=visit_unix_ts,
-    )
-
     _origin_content_view_test_helper(
         client,
         archive_data,
@@ -183,8 +168,6 @@
     root_dir_sha1 = head_rev["directory"]
     dir_content = archive_data.directory_ls(root_dir_sha1)
     branches, releases = process_snapshot_branches(snapshot)
-    visit_unix_ts = parse_timestamp(visit["date"]).timestamp()
-    visit_unix_ts = int(visit_unix_ts)
 
     _origin_directory_view_test_helper(
         client,
@@ -209,18 +192,6 @@
         visit_id=visit["visit"],
     )
 
-    _origin_directory_view_test_helper(
-        client,
-        archive_data,
-        origin,
-        visit,
-        branches,
-        releases,
-        root_dir_sha1,
-        dir_content,
-        timestamp=visit_unix_ts,
-    )
-
     _origin_directory_view_test_helper(
         client,
         archive_data,
@@ -268,18 +239,6 @@
         visit_id=visit["visit"],
     )
 
-    _origin_directory_view_test_helper(
-        client,
-        archive_data,
-        origin,
-        visit,
-        branches,
-        releases,
-        root_dir_sha1,
-        dir_content,
-        timestamp=visit_unix_ts,
-    )
-
     _origin_directory_view_test_helper(
         client,
         archive_data,
@@ -318,8 +277,6 @@
         e for e in archive_data.directory_ls(root_dir_sha1) if e["type"] == "dir"
     ]
     branches, releases = process_snapshot_branches(snapshot)
-    visit_unix_ts = parse_timestamp(visit["date"]).timestamp()
-    visit_unix_ts = int(visit_unix_ts)
 
     if len(subdirs) == 0:
         return
@@ -353,19 +310,6 @@
         visit_id=visit["visit"],
     )
 
-    _origin_directory_view_test_helper(
-        client,
-        archive_data,
-        origin,
-        visit,
-        branches,
-        releases,
-        root_dir_sha1,
-        subdir_content,
-        path=subdir_path,
-        timestamp=visit_unix_ts,
-    )
-
     _origin_directory_view_test_helper(
         client,
         archive_data,
@@ -417,19 +361,6 @@
         visit_id=visit["visit"],
     )
 
-    _origin_directory_view_test_helper(
-        client,
-        archive_data,
-        origin,
-        visit,
-        branches,
-        releases,
-        root_dir_sha1,
-        subdir_content,
-        path=subdir_path,
-        timestamp=visit_unix_ts,
-    )
-
     _origin_directory_view_test_helper(
         client,
         archive_data,
@@ -935,7 +866,7 @@
 
     if timestamp:
         query_params["timestamp"] = format_utc_iso_date(
-            parse_timestamp(timestamp).isoformat(), "%Y-%m-%dT%H:%M:%SZ"
+            parse_iso8601_date_to_utc(timestamp).isoformat(), "%Y-%m-%dT%H:%M:%SZ"
         )
 
     root_dir_url = reverse("browse-origin-directory", query_params=query_params)
@@ -1069,7 +1000,7 @@
 
     if timestamp:
         query_params["timestamp"] = format_utc_iso_date(
-            parse_timestamp(timestamp).isoformat(), "%Y-%m-%dT%H:%M:%SZ"
+            parse_iso8601_date_to_utc(timestamp).isoformat(), "%Y-%m-%dT%H:%M:%SZ"
         )
 
     for d in dirs:
diff --git a/swh/web/tests/browse/views/test_revision.py b/swh/web/tests/browse/views/test_revision.py
--- a/swh/web/tests/browse/views/test_revision.py
+++ b/swh/web/tests/browse/views/test_revision.py
@@ -10,7 +10,7 @@
 
 from swh.model.identifiers import DIRECTORY, REVISION, SNAPSHOT
 from swh.web.common.identifiers import gen_swhid
-from swh.web.common.utils import reverse, format_utc_iso_date, parse_timestamp
+from swh.web.common.utils import reverse, format_utc_iso_date, parse_iso8601_date_to_utc
 from swh.web.tests.django_asserts import assert_contains, assert_template_used
 from swh.web.tests.strategies import origin, revision, unknown_revision, new_origin
 
@@ -43,7 +43,7 @@
 
     revision_log_sorted = sorted(
         revision_log,
-        key=lambda rev: -parse_timestamp(rev["committer_date"]).timestamp(),
+        key=lambda rev: -parse_iso8601_date_to_utc(rev["committer_date"]).timestamp(),
     )
 
     url = reverse(
diff --git a/swh/web/tests/common/test_origin_visits.py b/swh/web/tests/common/test_origin_visits.py
--- a/swh/web/tests/common/test_origin_visits.py
+++ b/swh/web/tests/common/test_origin_visits.py
@@ -135,9 +135,6 @@
     visit = get_origin_visit(origin_info, visit_ts="2016-06-18 01:22")
     assert visit == visits[3]
 
-    visit = get_origin_visit(origin_info, visit_ts=1466208000)
-    assert visit == visits[3]
-
     visit = get_origin_visit(origin_info, visit_ts="2014-01-01")
     assert visit == visits[0]
 
diff --git a/swh/web/tests/common/test_utils.py b/swh/web/tests/common/test_utils.py
--- a/swh/web/tests/common/test_utils.py
+++ b/swh/web/tests/common/test_utils.py
@@ -5,7 +5,10 @@
 
 import datetime
 
+import pytest
+
 from swh.web.common import utils
+from swh.web.common.exc import BadInputExc
 
 
 def test_shorten_path_noop():
@@ -44,25 +47,33 @@
         assert utils.shorten_path(template % sha256) == template % short_sha256
 
 
-def test_parse_timestamp():
-    input_timestamps = [
-        None,
-        "2016-01-12",
-        "2016-01-12T09:19:12+0100",
-        "Today is January 1, 2047 at 8:21:00AM",
-        "1452591542",
-    ]
-
-    output_dates = [
-        None,
-        datetime.datetime(2016, 1, 12, 0, 0),
-        datetime.datetime(2016, 1, 12, 8, 19, 12, tzinfo=datetime.timezone.utc),
-        datetime.datetime(2047, 1, 1, 8, 21),
-        datetime.datetime(2016, 1, 12, 9, 39, 2, tzinfo=datetime.timezone.utc),
-    ]
-
-    for ts, exp_date in zip(input_timestamps, output_dates):
-        assert utils.parse_timestamp(ts) == exp_date
+@pytest.mark.parametrize(
+    "input_timestamp, output_date",
+    [
+        (
+            "2016-01-12",
+            datetime.datetime(2016, 1, 12, 0, 0, tzinfo=datetime.timezone.utc),
+        ),
+        (
+            "2016-01-12T09:19:12+0100",
+            datetime.datetime(2016, 1, 12, 8, 19, 12, tzinfo=datetime.timezone.utc),
+        ),
+        (
+            "2007-01-14T20:34:22Z",
+            datetime.datetime(2007, 1, 14, 20, 34, 22, tzinfo=datetime.timezone.utc),
+        ),
+    ],
+)
+def test_parse_iso8601_date_to_utc_ok(input_timestamp, output_date):
+    assert utils.parse_iso8601_date_to_utc(input_timestamp) == output_date
+
+
+@pytest.mark.parametrize(
+    "invalid_iso8601_timestamp", ["Today is January 1, 2047 at 8:21:00AM", "1452591542"]
+)
+def test_parse_iso8601_date_to_utc_ko(invalid_iso8601_timestamp):
+    with pytest.raises(BadInputExc):
+        utils.parse_iso8601_date_to_utc(invalid_iso8601_timestamp)
 
 
 def test_format_utc_iso_date():