From 379ba4300ec263ee26d28d35a8a3d7701968e5a4 Mon Sep 17 00:00:00 2001
From: Ryan Lewis <ryan@rlew.io>
Date: Sat, 13 Jun 2026 18:07:46 +0100
Subject: [PATCH] fix(when): stop rejecting weekday names like "monday"

`--when monday` was rejected with "did you mean today?" because
levenshtein("monday","today") == 2, inside the typo-detection
threshold. Weekday names are valid natural-language values that
Things accepts verbatim (and SKILL.md already documents them).

Allowlist weekday names and their abbreviations so they bypass the
keyword typo detector before nearKeyword runs.
---
 internal/things/dates.go      | 16 ++++++++++++++++
 internal/things/dates_test.go |  5 +++++
 2 files changed, 21 insertions(+)

diff --git a/internal/things/dates.go b/internal/things/dates.go
index 62b8de8..cc21746 100644
--- a/internal/things/dates.go
+++ b/internal/things/dates.go
@@ -9,10 +9,23 @@ import (
 
 var whenKeywords = []string{"today", "tomorrow", "evening", "anytime", "someday"}
 
+// weekdayWords are natural-language day names Things accepts verbatim. They are
+// allowlisted so the typo detector never mistakes them for a keyword — e.g.
+// "monday" is Levenshtein distance 2 from "today" and would otherwise be
+// rejected as a typo. Abbreviations are included for the same reason.
+var weekdayWords = []string{
+	"monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday",
+	"mon", "tue", "tues", "wed", "thu", "thur", "thurs", "fri", "sat", "sun",
+}
+
 func isWhenKeyword(s string) bool {
 	return slices.Contains(whenKeywords, s)
 }
 
+func isWeekdayWord(s string) bool {
+	return slices.Contains(weekdayWords, s)
+}
+
 // NormalizeWhen validates and canonicalises a --when value.
 //
 // Accepted forms:
@@ -37,6 +50,9 @@ func NormalizeWhen(s string) (string, error) {
 	if t, ok := parseISO8601(v); ok {
 		return t.Format("2006-01-02") + "@" + t.Format("15:04"), nil
 	}
+	if isWeekdayWord(strings.ToLower(v)) {
+		return v, nil
+	}
 	if k, ok := nearKeyword(v); ok {
 		return "", fmt.Errorf("unrecognised --when value %q (did you mean %q? valid keywords: %s)", v, k, strings.Join(whenKeywords, ", "))
 	}
diff --git a/internal/things/dates_test.go b/internal/things/dates_test.go
index 0364823..a71d594 100644
--- a/internal/things/dates_test.go
+++ b/internal/things/dates_test.go
@@ -25,6 +25,11 @@ func TestNormalizeWhen(t *testing.T) {
 		{"21:30", "21:30"},
 		{"next friday", "next friday"},
 		{"friday", "friday"},
+		{"monday", "monday"}, // dist 2 from "today" — must not be flagged as a typo
+		{"Monday", "Monday"}, // case preserved for NL pass-through
+		{"tuesday", "tuesday"},
+		{"sunday", "sunday"},
+		{"mon", "mon"},
 		{"tonight", "tonight"},
 		{"noon", "noon"},
 		{"2026-03-10T14:30:00Z", "2026-03-10@14:30"},