The hour unit has one home and it carries the dative plural (V-609)

"напомни к двум часам позвонить маме" now reads two o'clock. It read no
time at all, so the reminder reached the daemon with an empty slot and she
asked the open "Когда?" about an hour he had just said.

The word that lost it was "часам", the dative plural of "час". Four sets in
internal/router listed the hour noun and every one of them stopped at
"часу". They are now one lexicon key, hour_units, read by all four through
lexicon.HourUnits and lexicon.IsHourUnit. The minute noun had the same gap
one word over and gets the same treatment in minute_units: "минутам" was
missing everywhere "минут" and "минуты" were present. The slot_value_frame
set no longer lists either noun and appends both, so there is one copy of
each closed class rather than a copy per caller.

Two more sites had to move for the sentence to parse. hourPrepositions knew
"в", "во" and "на" and not "к", and the python dateparser rewrite knew the
same three. Both now read the fifth preposition and the oblique forms of the
hour that follow it.

Fixture unchanged: classifier+hash 27/91 before and after, reach 18/30
before and after, no case moved in either direction.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

internal/lexicon/lexicon_ru_v1.json

@@ -210,6 +210,20 @@
         "передумал", "передумала", "неактуально"
       ]
     },
+    "hour_units": {
+      "note": "Every form of the hour noun, Russian and English (V-609). One home for a closed class that four router sets used to list separately, and all four stopped at \"часу\": \"напомни к двум часам\" lost its hour and the reminder was left asking \"Когда?\". Russian declines, so the dative plural is as ordinary a way to say an hour as the accusative singular. A caller that folds time words into one set reads HourUnits; a caller asking about one word reads IsHourUnit.",
+      "words": [
+        "час", "часа", "часов", "часу", "часам", "часами", "часах",
+        "hour", "hours"
+      ]
+    },
+    "minute_units": {
+      "note": "Every form of the minute noun, Russian and English (V-609). Same class as hour_units one noun over, and it had the same gap: the dative plural \"минутам\" was missing everywhere \"минут\" and \"минуты\" were present.",
+      "words": [
+        "минута", "минуты", "минуту", "минут", "минуте", "минутам", "минутами", "минутах",
+        "minute", "minutes"
+      ]
+    },
     "slot_value_frame": {
       "note": "The words that can stand around a bare slot value without making the utterance a request of its own (Vikunja #560). Prepositions, hedges and the nouns a spoken time is built from: strip these, the numbers, the interrogatives, the filler particles and the other time sets, and whatever is left is the utterance's OWN content. \"а что если в 11:00\" leaves nothing and is an answer; \"какая сейчас погода в Риме\" leaves \"погода\" and \"Риме\" and is not. Closed because each part of it is closed — Russian has a fixed list of prepositions, and a clock is built from a fixed list of nouns. It is not a stopword list: a word goes in only if it can never be the thing he is asking about.",
       "words": [
@@ -217,10 +231,10 @@
         "at", "on", "in", "by", "to", "till", "until", "after", "before", "about", "for",
         "нет", "не", "да", "ага", "угу", "ой", "ох", "тогда", "лучше", "может", "можно", "наверное", "наверно", "пожалуй", "точнее", "скорее", "если", "пусть", "прости", "извини", "слушай", "значит", "как-то", "типа", "вообще-то",
         "no", "yes", "yeah", "ok", "okay", "sorry", "maybe", "actually", "rather", "then", "well",
-        "час", "часа", "часов", "часу", "часам", "минут", "минута", "минуты", "минуту", "минутах", "полдень", "полночь", "полдня",
+        "полдень", "полночь", "полдня",
         "утра", "утро", "утру", "дня", "день", "днями", "вечера", "вечер", "вечеру", "ночи", "ночь", "ночью",
         "сейчас", "теперь", "сегодняшний", "ближайший", "ближайшее",
-        "hour", "hours", "minute", "minutes", "noon", "midnight", "am", "pm", "oclock", "now"
+        "noon", "midnight", "am", "pm", "oclock", "now"
       ]
     },
     "dialogue_cancel": {