diff --git a/README.md b/README.md
index cd12a3a..7856998 100644
--- a/README.md
+++ b/README.md
@@ -179,7 +179,11 @@ its **beginning**, so `Reminisc.`, `Reminisc:` and `Reminiscere` all mean the sa
   Monday and 3 is Tuesday. A feria outside 1 to 7 is refused.
 * `Whit Monday`, `Easter Tuesday`, `Ostermontag` and `Pfingstdienstag` are also understood,
   with the weekday written as part of the word or as a separate word.
-* `Feria secunda`, `Fer. tertia` spell the number out; `prima` to `quarta` are understood.
+* `Feria secunda`, `Fer. tertia` spell the number out; `prima` to `septima` are understood.
+* With a feast that is not a Sunday, the feria names that feast's own weekday, where 1 is
+  Sunday: `Feria 6 in Parasceve` is Good Friday and `Feria V in Coena Domini` is Maundy
+  Thursday. Nothing is added to the date. The number is checked instead, so
+  `Fer. 2. Ascens.` is refused, because Ascension is a Thursday.
 
 **Days of a German feast:** Easter, Whitsun and Christmas were kept over several days, and
 German registers count them:
diff --git a/pyproject.toml b/pyproject.toml
index 54a567e..944c051 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "feastdate"
-version = "1.0.5"
+version = "1.0.6"
 description = "Convert church-year feast names from old parish registers (Dom. Palm. 1656) into calendar dates, Julian or Gregorian."
 readme = "README.md"
 license = { file = "LICENSE" }
diff --git a/src/feastdate/__init__.py b/src/feastdate/__init__.py
index 5bdab9f..de7568a 100644
--- a/src/feastdate/__init__.py
+++ b/src/feastdate/__init__.py
@@ -9,7 +9,7 @@
     g2o, greg_easter, j2o, julian_easter, o2g, o2j, resolve, show, to_ord,
 )
 
-__version__ = '1.0.5'
+__version__ = '1.0.6'
 
 __all__ = [
     'feast_date', 'resolve', 'show', 'FeastError',
diff --git a/src/feastdate/core.py b/src/feastdate/core.py
index 168d689..fb5800d 100644
--- a/src/feastdate/core.py
+++ b/src/feastdate/core.py
@@ -234,6 +234,7 @@ def show(o, cal):
 ADV = ('advent', 'adv')
 EPIPH = ('epiph',)
 FERIA = ('feria', 'fer')
+FERIA_DAY = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
 # Weekday words English transcriptions use after a feast name: `Whit Monday`.
 WEEKDAY_WORDS = {'monday': 1, 'tuesday': 2, 'montag': 1, 'dienstag': 2}
 # Weekday words that only say which day the feast fell on. The answer must agree.
@@ -265,7 +266,8 @@ def show(o, cal):
 FEAST_DAYS = 3              # the most days any feast was kept; 'letzter' is the third
 # Ordinals written out. The register writes `der dritte Ostertag`, `Feria secunda`.
 ORD_WORDS = [(r'(?:erst|zweit|dritt|viert)(?:e|er|en|es|em)?', ('erst', 'zweit', 'dritt', 'viert')),
-             (r'(?:prim|secund|terti|quart)(?:a|o|ae|am|us|um|i)?', ('prim', 'secund', 'terti', 'quart')),
+             (r'(?:prim|secund|terti|quart|quint|sext|septim)(?:a|o|ae|am|us|um|i)?',
+              ('prim', 'secund', 'terti', 'quart', 'quint', 'sext', 'septim')),
              (r'(?:first|second|third|fourth)', ('first', 'second', 'third', 'fourth'))]
 LAST_RE = r'letzt(?:e|er|en|es|em)?'
 # Words that connect a feast name to the rest of the entry and add nothing to the date.
@@ -500,7 +502,13 @@ def refuse_unless(ok, why):
         extra = 0
         if feria:
             refuse_unless(kind == 'easter', 'feria counts from a movable feast')
-            extra = n - 1                           # feria 2 = Monday, 3 = Tuesday
+            if off % 7:
+                # A weekday feast: `Feria 6 in Parasceve` is Good Friday itself. The number
+                # names the feast's own weekday (feria 1 = Sunday), so it is a check.
+                refuse_unless((n - 2) % 7 == o % 7, 'feria %d does not fall on %s, a %s'
+                              % (n, hit, FERIA_DAY[o % 7]))
+            else:
+                extra = n - 1                       # feria 2 = Monday, 3 = Tuesday
         elif tag and n is not None:
             refuse_unless((kind, key) in DAY_FEASTS,
                           'only Ostertag, Pfingsttag and Weihnachtstag count their days')
diff --git a/tests/test_feastdate.py b/tests/test_feastdate.py
index a11ecb3..59e5239 100644
--- a/tests/test_feastdate.py
+++ b/tests/test_feastdate.py
@@ -115,6 +115,10 @@ def test_the_1700_switch():
     ('Fer. 9. Pasch. 1680', '^feria counts the days of the week, 1 to 7, not 9'),
     ('Fer. 0. Pent. 1680', '^feria counts the days of the week, 1 to 7, not 0'),
     ('Fer. 8. Trin. 1680', '^feria counts the days of the week, 1 to 7, not 8'),
+    # With a weekday feast the feria names the feast's own weekday, not an offset (#3).
+    ('Fer. 2. Ascens. 1680', '^feria 2 does not fall on ascens, a Thursday'),
+    ('Feria 2 in Parasceve 1680', '^feria 2 does not fall on parasceve, a Friday'),
+    ('Feria 6 in Coena Domini 1680', '^feria 6 does not fall on coena, a Thursday'),
 ])
 def test_refused(bad, why):
     # Anchored on each branch's own wording: the catch-all quotes the input back, so a
@@ -283,6 +287,12 @@ def test_cal_of_year_answers_for_the_day():
     ('2. Christtag 1740', 'Mon 26 Dec 1740 (Gregorian)'),
     ('Feria secunda Paschatos 1740', 'Mon 18 Apr 1740 (Gregorian)'),
     ('Fer. tertia Pent. 1740', 'Tue 7 Jun 1740 (Gregorian)'),
+    # A weekday feast: the feria is the feast's own weekday and adds nothing (#3).
+    ('Feria 6 in Parasceve 1680', 'Fri 9 Apr 1680 (Julian)'),
+    ('Feria sexta in Parasceve 1680', 'Fri 9 Apr 1680 (Julian)'),
+    ('Feria V in Coena Domini 1680', 'Thu 8 Apr 1680 (Julian)'),
+    ('Feria quinta in Coena Domini 1680', 'Thu 8 Apr 1680 (Julian)'),
+    ('Fer. 5. Ascens. 1680', 'Thu 20 May 1680 (Julian)'),
 ])
 def test_day_of_the_feast(text, want):
     assert feast_date(text) == want