diff --git a/sunset-alarm b/sunset-alarm
index 9d0d774..3e56180 100755
--- a/sunset-alarm
+++ b/sunset-alarm
@@ -1,140 +1,77 @@
 #!/usr/bin/env bash
-# sunset-alarm — alert at a specified number of minutes before sunset
+# sunset-alarm — persistent alert at a calculated offset before sunset
 # Usage: sunset-alarm (-l LAT:LONG | -t HH24:MI) (-m MINUTES) [-h]
-set -euo pipefail
+set -uo pipefail
 
-SUNSET=""         # epoch seconds for today's sunset
-ALERT_EPOCH=""    # epoch when alert should fire (sunset - offset)
-OFFSET_MIN=0      # signed minute offset from sun -t/--hardcoded
-LAT="" LON=""     # coordinates  (-l/--location)
-HARDCODED_TIME="" # HH:MM string              (-t/--hardcoded)
+SUNSET_EPOCH=""     # epoch of today's sunset
+ALERT_EPOCH=""      # epoch when the window opens (sunset - offset)
+OFFSET_MIN=0        # signed minute offset from sunset
+LAT=""              # latitude   (-l/--location)
+LON=""              # longitude
+HARDCODED_TIME=""  # HH:MM string (-t/--hardcoded)
 
-# ── helpers ────────────────────────────────────────────────────────
 usage() {
     cat <<'EOF'
 Usage: sunset-alarm (-l LAT:LONG | -t HH24:MI) (-m MINUTES) [-h]
 
 Options:
-  -l LAT:LONG        Latitude and longitude (e.g. 32.123:-111.111)
-  -t HH24:MI         Hardcoded sunset time (ignored when combined with -l)
-  -m MINUTES         Minutes offset before (+) or after (-) sunset to alert
-  -h                 Show this help and exit
+  -l LAT:LONG        Latitude and longitude, e.g. 32.123:-111.111
+                     (queried from Open-Meteo for today's sunset time)
+  -t HH24:MI         Hardcoded sunset time to use instead.
+                     When combined with -l the offset is applied against
+                     this time and the network call is skipped.
+  -m MINUTES         Minutes before (-), at (= 0), or after (+) sunset
+                     to trigger the alert.  May be negative.
+  -h                 Show this help message and exit.
+
+Examples:
+  sunset-alarm -l 32.123:-111.111 -m 90   # 90 min before actual sunset
+  sunset-alarm -t 18:00 -m -5             # 5 min after the hardcoded time
 EOF
 }
 
-die() { echo "ERROR: $*" >&2; exit 1; }
+die() { echo "Error: $*" >&2; exit 1; }
 
-warn_reconnect() { echo "Network unavailable, retrying in 5 minutes…" >&2; }
+# ── resolve a fallback command at startup ──────────────────────────
+NOTIFY_CMD=""
+for _cmd in fyi notify-send wall; do
+    if command -v "$_cmd" >/dev/null 2>&1; then
+        NOTIFY_CMD="$_cmd"; break
+    fi
+done
 
-# Query Open-Meteo for today's sunset epoch (local timezone).
+fire_alert() {
+    local body="$1"
+    case "$NOTIFY_CMD" in
+        fyi)         fyi "Sunset Alarm: ${body}" ;;
+        notify-send) notify-send -u normal "Sunset Alarm" "${body}" 2>/dev/null || true ;;
+        wall)        echo "Sunset Alarm: ${body}" | wall 2>/dev/null || printf 'Sunset Alarm: %s\n' "$body" ;;
+    esac
+}
+
+# ── open-meteo helper ─────────────────────────────────────────────
 fetch_sunset_epoch() {
     local lat="$1" lon="$2"
-    local json resp_code
-    # curl –silent + show HTTP code (-w) so we can detect server errors.
-    json=$(curl -sf -w '\n%{http_code}' \
+    # curl –silent + HTTP code tail so we can detect failures.
+    local resp; resp=$(curl -sfw "\n%{http_code}" \
         "https://api.open-meteo.com/v1/forecast?latitude=${lat}&longitude=${lon}&current=sunset&timezone=auto" \
         --connect-timeout 10 --max-time 30) || return 1
-    resp_code="${json##*$'\n'}"
-    json="${json%$'\n'*}"
-    [[ "$resp_code" == "200" ]] || return 2
-    # jq → "YYYY-MM-DDTHH:MM" (ISO-8601 local-time string for the sunset field)
-    local iso_ts
-    iso_ts=$(echo "$json" | jq -r '.current.sunset' | grep -v '^null$')
-    [[ -n "$iso_ts" ]] || return 3
-    # date -d parses ISO-8601 timestamps directly.
-    SUNSET=$(date -d "$iso_ts" +%s)
+
+    local code="${resp##*$'\n'}"
+    resp="${resp%$'\n'*}"                          # strip the trailing HTTP code
+
+    [[ "${code:-599}" == "200" ]] || return 2
+
+    local iso; iso=$(printf '%s\n' "$resp" | jq -r '.current.sunset // empty')
+    [[ -n "$iso" ]] || return 3                    # null / missing field
+
+    SUNSET_EPOCH=$(date -d "$iso" +%s)             # local-time epoch
 }
 
-# Build today's sunset epoch from HH:MM when using the hardcoded path (-t).
+# Build today's sunset epoch from a hardcoded HH:MM when -t is used.
 set_sunset_from_time() {
-    local hhmm="$1" hh mm
-    read -r hh mm <<< "$(echo "$hhmm" | tr ':' ' ')"
-    # Pad hours / minutes in case user passed "8:30" etc. (they won't via arg
-    # parsing, but defensive never hurts).
-    SUNSET=$(date -d "$(date +%Y-%m-%d) ${hh}:${mm}:00" +%s)
-}
-
-# Fire a desktop notification (best-effort).
-notify() {
-    local title="$1" body="$2"
-    notify-send -u normal "$title" "$body" 2>/dev/null || true
-    printf '%s — %s\n' "$(date '+%F %T')" "ALERT: $body"
-}
-
-# ── argument parsing ───────────────────────────────────────────────
-while [[ $# -gt 0 ]]; do
-    case "$1" in
-        -l)
-            [[ $# -ge 2 ]] || die "-l requires an argument (LAT:LONG)"
-            IFS=':' read -r LAT LON <<< "$2"
-            shift 2
-            ;;
-        -t)
-            [[ $# -ge 2 ]] || die "-t requires an argument (HH24:MI)"
-            HARDCODED_TIME="$2"
-            shift 2
-            ;;
-        -m)
-            [[ $# -ge 2 ]] || die "-m requires an argument (MINUTES)"
-            OFFSET_MIN="$2"
-            shift 2
-            ;;
-        -h|--help) usage; exit 0 ;;
-        *)         die "Unknown option: $1" ;;
-    esac
-done
-
-# ── guardrails ─────────────────────────────────────────────────────
-[[ $# -eq 0 ]] || die "extra arguments provided — see --help"
-(( OFFSET_MIN >= -60 )) || [[ $OFFSET_MIN -le 0 ]] 2>/dev/null \
-    1>/dev/null || die "-m must be ≥ -60 (or any value ≤ 0)"
-
-# Need either -l or -t.
-if [[ -z "$LAT" && -z "$HARDCODED_TIME" ]]; then
-    die "Need at least one of: -l LAT:LONG, -t HH24:MI"
-fi
-
-# ── Phase 1 — resolve today's sunset (epoch) ───────────────────────
-if [[ -n "$LAT" && -n "$LON" ]]; then
-    while true; do
-        fetch_sunset_epoch "$LAT" "$LON" && break
-        delay=$(( 5 * 60 ))
-        warn_reconnect; sleep "$delay" || warn_reconnect
-    done
-else
-    set_sunset_from_time "$HARDCODED_TIME"
-fi
-
-# ── Phase 2 — compute alert time and loop ──────────────────────────
-ALERT_EPOCH=$(( SUNSET - OFFSET_MIN * 60 ))
-now_epoch=$(date +%s)
-
-if (( now_epoch >= ALERT_EPOCH )); then
-    # Already past the window — fire once, exit.
-    notify "Sunset Alarm" \
-        "Triggered (offset: ${OFFSET_MIN:++}$(printf '%d' "$OFFSET_MIN")). Sunset at $(date -d @"$SUNSET" '+%H:%M')."
-    exit 0
-fi
-
-while true; do
-    now_epoch=$(date +%s)
-    if (( ALERT_EPOCH <= now_epoch && now_epoch < SUNSET )); then
-        notify "Sunset Alarm" \
-            "Triggered (offset: ${OFFSET_MIN:++}$(printf '%d' "$OFFSET_MIN")). Sunset at $(date -d @"$SUNSET" '+%H:%M')."
-    elif (( now_epoch > SUNSET )); then
-        # Day is over — re-fetch for tomorrow (if we have -l).
-        if [[ -n "$LAT" && -n "$LON" ]]; then
-            warn_reconnect=true   # just print a quick line, don't sleep
-            while true; do
-                fetch_sunset_epoch "$LAT" "$LON" && break
-                delay=$(( 5 * 60 ))
-                warn_reconnect; sleep "$delay" || warn_reconnect
-            done
-        else
-            set_sunset_from_time "$HARDCODED_TIME"
-        fi
-        ALERT_EPOCH=$(( SUNSET - OFFSET_MIN * 60 ))
-        continue
-    fi
-    sleep 60
-done
+    local hhmm="$1"
+    local Y M D h m
+    read -r Y M D h m <<< "$(date +%Y-%m-%d) $(echo "$hhmm" | tr ':' ' ')"
+    SUNSET_EPOCH=$(date -d "${Y}-${M}-${D} ${h}:${m}:00" 2>/dev/null +%s \
+                 || die "Invalid time format '${hhmm}')")