fix: migration

internal/service/reminder_service.go

@@ -105,9 +105,11 @@ func (s *ReminderService) SetEnabled(ctx context.Context, userID string, enabled
 }
 
 // SetTimezone validates the IANA zone before storing so a bad value can never
-// break the (timezone-using) candidate scan.
+// break the (timezone-using) candidate scan. Legacy aliases are canonicalized
+// first (browsers report e.g. "Asia/Calcutta"): Go resolves them but a
+// Postgres without the tzdata backward links rejects them in AT TIME ZONE.
 func (s *ReminderService) SetTimezone(ctx context.Context, userID, tz string) error {
-	tz = strings.TrimSpace(tz)
+	tz = canonicalTZ(strings.TrimSpace(tz))
 	if tz == "" {
 		tz = "UTC"
 	}

internal/service/sadhna_service.go

@@ -94,6 +94,11 @@ const fallbackTZ = "Asia/Kolkata"
 // genuine UTC user re-reports their real zone on next load.
 func (s *SadhnaService) resolveTZ(ctx context.Context, userID string) (string, *time.Location) {
 	tz, _ := s.logs.UserTimezone(ctx, userID)
+	// Canonicalize legacy aliases (e.g. stored "Asia/Calcutta") — the name
+	// is fed into SQL AT TIME ZONE, which rejects aliases on a Postgres
+	// without the tzdata backward links. Covers rows written before
+	// SetTimezone started canonicalizing.
+	tz = canonicalTZ(tz)
 	if tz == "" || tz == "UTC" {
 		tz = fallbackTZ
 	}

internal/service/timezone.go

@@ -0,0 +1,89 @@
+package service
+
+// Legacy IANA timezone aliases → canonical names.
+//
+// Browsers report Intl.DateTimeFormat().resolvedOptions().timeZone, and the
+// ICU/CLDR data they ship still uses several LEGACY ids as its canonical
+// form — Safari and Chrome genuinely say "Asia/Calcutta", not "Asia/Kolkata".
+// Go's time.LoadLocation resolves these aliases, so they pass validation and
+// get stored; but a Postgres built against tzdata without the "backward"
+// links (Debian/Alpine images with the tzdata-legacy split) rejects them in
+// AT TIME ZONE with SQLSTATE 22023. Everything we store or hand to SQL goes
+// through canonicalTZ first.
+var legacyTZ = map[string]string{
+	// Ids ICU/CLDR still reports as canonical (the ones browsers send).
+	"Asia/Calcutta":        "Asia/Kolkata",
+	"Asia/Katmandu":        "Asia/Kathmandu",
+	"Asia/Rangoon":         "Asia/Yangon",
+	"Asia/Saigon":          "Asia/Ho_Chi_Minh",
+	"America/Buenos_Aires": "America/Argentina/Buenos_Aires",
+	"America/Catamarca":    "America/Argentina/Catamarca",
+	"America/Cordoba":      "America/Argentina/Cordoba",
+	"America/Jujuy":        "America/Argentina/Jujuy",
+	"America/Mendoza":      "America/Argentina/Mendoza",
+	"America/Indianapolis": "America/Indiana/Indianapolis",
+	"America/Louisville":   "America/Kentucky/Louisville",
+	"America/Godthab":      "America/Nuuk",
+	"Atlantic/Faeroe":      "Atlantic/Faroe",
+	"Pacific/Ponape":       "Pacific/Pohnpei",
+	"Pacific/Truk":         "Pacific/Chuuk",
+	"Europe/Kiev":          "Europe/Kyiv",
+
+	// Other common backward links, in case a zone arrives from an older
+	// client or was set by hand.
+	"Asia/Ashkhabad":        "Asia/Ashgabat",
+	"Asia/Chongqing":        "Asia/Shanghai",
+	"Asia/Chungking":        "Asia/Shanghai",
+	"Asia/Dacca":            "Asia/Dhaka",
+	"Asia/Harbin":           "Asia/Shanghai",
+	"Asia/Istanbul":         "Europe/Istanbul",
+	"Asia/Kashgar":          "Asia/Urumqi",
+	"Asia/Macao":            "Asia/Macau",
+	"Asia/Tel_Aviv":         "Asia/Jerusalem",
+	"Asia/Thimbu":           "Asia/Thimphu",
+	"Asia/Ujung_Pandang":    "Asia/Makassar",
+	"Asia/Ulan_Bator":       "Asia/Ulaanbaatar",
+	"Africa/Asmera":         "Africa/Asmara",
+	"America/Coral_Harbour": "America/Atikokan",
+	"Australia/ACT":         "Australia/Sydney",
+	"Australia/Canberra":    "Australia/Sydney",
+	"Australia/NSW":         "Australia/Sydney",
+	"Australia/North":       "Australia/Darwin",
+	"Australia/Queensland":  "Australia/Brisbane",
+	"Australia/South":       "Australia/Adelaide",
+	"Australia/Tasmania":    "Australia/Hobart",
+	"Australia/Victoria":    "Australia/Melbourne",
+	"Australia/West":        "Australia/Perth",
+	"US/Alaska":             "America/Anchorage",
+	"US/Arizona":            "America/Phoenix",
+	"US/Central":            "America/Chicago",
+	"US/Eastern":            "America/New_York",
+	"US/Hawaii":             "Pacific/Honolulu",
+	"US/Mountain":           "America/Denver",
+	"US/Pacific":            "America/Los_Angeles",
+	"GB":                    "Europe/London",
+	"GB-Eire":               "Europe/London",
+	"Eire":                  "Europe/Dublin",
+	"Egypt":                 "Africa/Cairo",
+	"Hongkong":              "Asia/Hong_Kong",
+	"Iceland":               "Atlantic/Reykjavik",
+	"Israel":                "Asia/Jerusalem",
+	"Japan":                 "Asia/Tokyo",
+	"NZ":                    "Pacific/Auckland",
+	"Poland":                "Europe/Warsaw",
+	"Portugal":              "Europe/Lisbon",
+	"PRC":                   "Asia/Shanghai",
+	"ROC":                   "Asia/Taipei",
+	"ROK":                   "Asia/Seoul",
+	"Singapore":             "Asia/Singapore",
+	"Turkey":                "Europe/Istanbul",
+}
+
+// canonicalTZ returns the canonical IANA name for tz, resolving legacy
+// aliases; unknown values pass through unchanged.
+func canonicalTZ(tz string) string {
+	if c, ok := legacyTZ[tz]; ok {
+		return c
+	}
+	return tz
+}