diff --git a/4-seasons.sh b/4-seasons.sh
index 58595a0..213361c 100755
--- a/4-seasons.sh
+++ b/4-seasons.sh
@@ -90,16 +90,32 @@ speed_factor=$(echo "scale=6; $raw_duration / $target_per_clip" | bc)
 echo "Step 2/2: speed factor $speed_factor..."
 
 final_file="$output_dir/${yesterday}_Mvt${MVT_NUM}-Day${DAY_OF_MVT}of${DAYS_IN_MVT}-final.mp4"
-ffmpeg -loglevel warning \
+if ! ffmpeg -loglevel warning \
     -i "$temp_video" \
     -vf "setpts=PTS/$speed_factor" \
     -c:v libx264 -pix_fmt yuv420p -crf "$CRF_SEASONS_FINAL" \
     -t "$target_per_clip" -an \
-    -y "$final_file"
+    -y "$final_file"; then
+    rm -f "$final_file"
+    "$SCRIPT_DIR/notify.sh" "FAILED: $SEASON Mvt$MVT_NUM Day$DAY_OF_MVT speed-adjust ($yesterday)" \
+        "ffmpeg speed-adjust failed — re-run 4-seasons.sh $CAM_NAME while JPGs exist" || true
+    exit 1
+fi
 
 adjusted=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$final_file")
 echo "Daily clip: $final_file  ($adjusted s)"
 
+# Warn if clip duration deviates more than 0.5 s from target (float drift check)
+drift=$(echo "scale=3; $adjusted - $target_per_clip" | bc | sed 's/^-//')
+if awk "BEGIN{exit !($drift > 0.5)}"; then
+    echo "WARNING: clip duration ${adjusted}s differs from target ${target_per_clip}s by ${drift}s"
+    "$SCRIPT_DIR/notify.sh" "WARNING: $SEASON Mvt$MVT_NUM Day$DAY_OF_MVT duration drift ($yesterday)" \
+        "Clip ${adjusted}s vs target ${target_per_clip}s (drift ${drift}s)" || true
+fi
+
+"$SCRIPT_DIR/notify.sh" "$SEASON Mvt$MVT_NUM Day$DAY_OF_MVT/$DAYS_IN_MVT saved ($yesterday)" \
+    "$(basename "$final_file") — ${adjusted}s" || true
+
 # ── Auto-trigger montage on last day of movement ──────────────────────────────
 if [ "$IS_LAST_DAY" = "true" ]; then
     echo "Last day of $SEASON Mvt $MVT_NUM — triggering montage compilation..."
diff --git a/daily_sunrise_video.sh b/daily_sunrise_video.sh
index 11a2a20..97e0869 100644
--- a/daily_sunrise_video.sh
+++ b/daily_sunrise_video.sh
@@ -4,6 +4,12 @@
 # side, and write the final video.  Upload is handled by a separate systemd
 # service (sky-cam-sunrise-upload) triggered via OnSuccess= so the two jobs
 # have independent log entries and failure states.
+#
+# Resilience: the speed-adjusted video is saved permanently before the overlay
+# step.  If overlay fails, the sped video survives at:
+#   <output_dir>/<date>-daily-sunrise-sped.mp4
+# Re-run this script once the issue is resolved; the sped file is deleted
+# automatically when the overlay step succeeds.
 
 set -euo pipefail
 
@@ -22,6 +28,8 @@ mkdir -p "$output_dir"
 # ── Sunrise time ──────────────────────────────────────────────────────────────
 sunrise_time=$(python3 "$SCRIPT_DIR/sunrise.py")
 if [[ -z "$sunrise_time" ]]; then
+    "$SCRIPT_DIR/notify.sh" "FAILED: sunrise $current_date" \
+        "Could not retrieve sunrise time from sunrise.py" || true
     echo "Error: Failed to retrieve sunrise time."
     exit 1
 fi
@@ -40,11 +48,14 @@ echo "Window: $((start_sec/3600)):$(printf '%02d' $(((start_sec%3600)/60))) →
 
 # ── Collect images in window ──────────────────────────────────────────────────
 if [ ! -d "$image_dir" ]; then
+    "$SCRIPT_DIR/notify.sh" "FAILED: sunrise $current_date" \
+        "Image directory not found: $image_dir" || true
     echo "Error: image directory not found: $image_dir"
     exit 1
 fi
 
 temp_list=$(mktemp --suffix=.txt)
+raw_video=""
 trap 'rm -f "$temp_list" "$raw_video" 2>/dev/null || true' EXIT
 
 find "$image_dir" -type f -name "*.jpg" | sort | while read -r img; do
@@ -56,6 +67,8 @@ done > "$temp_list"
 
 num_images=$(wc -l < "$temp_list")
 if [[ $num_images -lt 1 ]]; then
+    "$SCRIPT_DIR/notify.sh" "FAILED: sunrise $current_date" \
+        "No images found in sunrise window" || true
     echo "No images found in sunrise window."
     exit 1
 fi
@@ -78,17 +91,39 @@ fi
 
 # ── Step 1: Raw video from images ─────────────────────────────────────────────
 raw_video=$(mktemp --suffix=.mp4)
-echo "Step 1/2: encoding raw video..."
-ffmpeg -loglevel warning \
+echo "Step 1/3: encoding raw video..."
+if ! ffmpeg -loglevel warning \
     -f concat -safe 0 -i "$temp_list" \
     -c:v libx264 -pix_fmt yuv420p -crf "$CRF_SUNRISE" -vsync 2 -an \
-    -y "$raw_video"
+    -y "$raw_video"; then
+    "$SCRIPT_DIR/notify.sh" "FAILED: sunrise step 1/3 (encode) $current_date" \
+        "ffmpeg raw encode from images failed — check: journalctl -u sky-cam-sunrise.service" || true
+    exit 1
+fi
 
 raw_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$raw_video")
 speed_factor=$(echo "scale=3; $raw_dur / $SUNRISE_TARGET_SECS" | bc)
 echo "Raw: ${raw_dur}s  speed factor: ${speed_factor}x"
 
-# ── Step 2: Speed-adjust + sunrise time overlay ───────────────────────────────
+# ── Step 2: Speed-adjust — saved permanently so overlay failure is recoverable ─
+# Deleted automatically if step 3 succeeds.
+sped_video="$output_dir/$current_date-daily-sunrise-sped.mp4"
+echo "Step 2/3: speed-adjust → $sped_video"
+if ! ffmpeg -loglevel warning \
+    -i "$raw_video" \
+    -vf "setpts=PTS/${speed_factor}" \
+    -c:v libx264 -pix_fmt yuv420p -crf "$CRF_SUNRISE" -an \
+    -y "$sped_video"; then
+    rm -f "$sped_video"
+    "$SCRIPT_DIR/notify.sh" "FAILED: sunrise step 2/3 (speed) $current_date" \
+        "speed-adjust failed — no video saved" || true
+    exit 1
+fi
+
+sped_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$sped_video")
+echo "Speed-adjusted: ${sped_dur}s  (saved — overlay still pending)"
+
+# ── Build overlay filter ──────────────────────────────────────────────────────
 # Time displayed as stacked characters down the right side (e.g. 0/7/:/2/3),
 # semi-transparent with a soft drop shadow so it reads on any background.
 SR_TIME=$(echo "$sunrise_time_local" | cut -d'-' -f1,2 | tr '-' ':')
@@ -104,14 +139,23 @@ DT="${DT}:line_spacing=4"
 DT="${DT}:x=w-tw-18:y=(h-th)/2"
 DT="${DT}:shadowcolor=black@0.55:shadowx=1:shadowy=1"
 
+# ── Step 3: Overlay — sunrise time burned in ──────────────────────────────────
+# If this fails, $sped_video survives at its permanent path for manual recovery.
 final_video="$output_dir/$current_date-daily-sunrise.mp4"
-echo "Step 2/2: speed-adjust + overlay → $final_video"
-
-ffmpeg -loglevel warning \
-    -i "$raw_video" \
-    -vf "setpts=PTS/${speed_factor},${DT}" \
+echo "Step 3/3: overlay → $final_video"
+if ! ffmpeg -loglevel warning \
+    -i "$sped_video" \
+    -vf "${DT}" \
     -c:v libx264 -pix_fmt yuv420p -crf "$CRF_SUNRISE" -an \
-    -y "$final_video"
+    -y "$final_video"; then
+    "$SCRIPT_DIR/notify.sh" "FAILED: sunrise overlay $current_date" \
+        "Overlay failed — speed-only video saved: $(basename "$sped_video")" || true
+    exit 1
+fi
 
 actual_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$final_video")
 echo "Done: $final_video  (${actual_dur}s, sunrise at ${SR_TIME})"
+
+rm -f "$sped_video"
+"$SCRIPT_DIR/notify.sh" "Sunrise ready: $current_date" \
+    "$(basename "$final_video") — ${actual_dur}s, sunrise at ${SR_TIME}" || true
diff --git a/montage-mvt.sh b/montage-mvt.sh
index c22d6dc..5929ce2 100755
--- a/montage-mvt.sh
+++ b/montage-mvt.sh
@@ -51,6 +51,8 @@ mkdir -p "$output_dir"
 
 music_file=$(find "$music_base_dir" -type f -iname "*${SEASON}*Mvt*${MVT_NUM}*" | sort | head -n 1)
 if [ -z "$music_file" ]; then
+    "$SCRIPT_DIR/notify.sh" "FAILED: montage $SEASON Mvt$MVT_NUM ($ASTRO_YEAR)" \
+        "Music file not found in $music_base_dir" || true
     echo "ERROR: Music file not found for $SEASON Mvt $MVT_NUM in $music_base_dir"
     exit 1
 fi
@@ -60,11 +62,28 @@ echo "Music: $(basename "$music_file")  (${music_duration}s)"
 # ── Collect sorted daily clips ────────────────────────────────────────────────
 mapfile -d '' daily_clips < <(find "$video_dir" -maxdepth 1 -name "*-final.mp4" -print0 | sort -z)
 if [ "${#daily_clips[@]}" -eq 0 ]; then
+    "$SCRIPT_DIR/notify.sh" "FAILED: montage $SEASON Mvt$MVT_NUM ($ASTRO_YEAR)" \
+        "No *-final.mp4 clips found in $video_dir" || true
     echo "ERROR: No *-final.mp4 clips in $video_dir"
     exit 1
 fi
 echo "Found ${#daily_clips[@]} daily clips"
 
+# ── Validate clip duration sum against music ──────────────────────────────────
+total_clip_dur=0
+for clip in "${daily_clips[@]}"; do
+    d=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$clip")
+    total_clip_dur=$(echo "scale=3; $total_clip_dur + $d" | bc)
+done
+clip_drift=$(echo "scale=3; $total_clip_dur - $music_duration" | bc | sed 's/^-//')
+echo "Sum of clips: ${total_clip_dur}s  Music: ${music_duration}s  Drift: ${clip_drift}s"
+if awk "BEGIN{exit !($clip_drift > 2.0)}"; then
+    echo "WARNING: clip total differs from music by ${clip_drift}s — speed pass will compensate"
+    "$SCRIPT_DIR/notify.sh" \
+        "WARNING: $SEASON Mvt$MVT_NUM clip drift ${clip_drift}s ($ASTRO_YEAR)" \
+        "Clips sum ${total_clip_dur}s vs music ${music_duration}s" || true
+fi
+
 # ── Source resolution ─────────────────────────────────────────────────────────
 VIDEO_W=$(ffprobe -v error -select_streams v:0 -show_entries stream=width  -of csv=p=0 "${daily_clips[0]}")
 VIDEO_H=$(ffprobe -v error -select_streams v:0 -show_entries stream=height -of csv=p=0 "${daily_clips[0]}")
@@ -105,18 +124,25 @@ pad=${VIDEO_W}:${VIDEO_H}:(ow-iw)/2:(oh-ih)/2,setsar=1" \
     -c:v libx264 -pix_fmt yuv420p -crf "$CRF_MONTAGE" -an \
     -y "$temp_concat"
 
-# ── Step 2: Speed-adjust to match music duration exactly ──────────────────────
+# ── Step 2: Speed-adjust — saved permanently so music/overlay failure is recoverable ─
+# Deleted automatically if step 3 succeeds.
 concat_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$temp_concat")
 speed_factor=$(echo "scale=6; $concat_dur / $music_duration" | bc)
 echo "Step 2/3: speed $speed_factor  (raw=${concat_dur}s → music=${music_duration}s)"
 
-temp_sped=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_sped")
-ffmpeg -loglevel warning \
+sped_file="$output_dir/${MVT_START}_${SEASON}_Mvt${MVT_NUM}-Sped.mp4"
+if ! ffmpeg -loglevel warning \
     -i "$temp_concat" \
     -vf "setpts=PTS/$speed_factor" \
     -c:v libx264 -pix_fmt yuv420p -crf "$CRF_MONTAGE" -an \
-    -t "$music_duration" -y "$temp_sped"
+    -t "$music_duration" -y "$sped_file"; then
+    rm -f "$sped_file"
+    "$SCRIPT_DIR/notify.sh" "FAILED: montage step 2/3 (speed) $SEASON Mvt$MVT_NUM ($ASTRO_YEAR)" \
+        "speed-adjust failed — concat temp lost; re-run montage-mvt.sh" || true
+    exit 1
+fi
 rm "$temp_concat"
+echo "Speed-adjusted: $sped_file  (saved — music+overlay still pending)"
 
 # ── Step 3: Music + fades + attribution overlay ───────────────────────────────
 # Attribution overlay: semi-transparent bar across the top for the first
@@ -152,16 +178,21 @@ DT="${DT}:alpha='${ALPHA}':enable='${ENABLE}'"
 
 output_file="$output_dir/${MVT_START}_${SEASON}_Mvt${MVT_NUM}-Montage.mp4"
 
-ffmpeg -loglevel warning \
-    -i "$temp_sped" -i "$music_file" \
+# If this fails, $sped_file survives for manual recovery (re-run step 3 only).
+if ! ffmpeg -loglevel warning \
+    -i "$sped_file" -i "$music_file" \
     -filter_complex \
 "[0:v]fade=t=in:st=0:d=${FADE_DUR},fade=t=out:st=${fade_out_start}:d=${FADE_DUR},${DT}[vout];\
 [1:a]afade=t=in:st=0:d=${FADE_DUR},afade=t=out:st=${fade_out_start}:d=${FADE_DUR}[aout]" \
     -map "[vout]" -map "[aout]" \
     -c:v libx264 -pix_fmt yuv420p -c:a aac -b:a "$AUDIO_BITRATE" \
-    -t "$music_duration" -y "$output_file"
-rm "$temp_sped"
+    -t "$music_duration" -y "$output_file"; then
+    "$SCRIPT_DIR/notify.sh" "FAILED: montage step 3/3 (music+overlay) $SEASON Mvt$MVT_NUM ($ASTRO_YEAR)" \
+        "Music/overlay failed — sped video saved: $(basename "$sped_file")" || true
+    exit 1
+fi
 
+rm -f "$sped_file"
 echo "Done: $output_file"
 
 # ── Notify ────────────────────────────────────────────────────────────────────
diff --git a/year-end-join.sh b/year-end-join.sh
index 4da4746..178fb59 100755
--- a/year-end-join.sh
+++ b/year-end-join.sh
@@ -32,6 +32,7 @@ concat_list=$(mktemp --suffix=.txt)
 trap 'rm -f "$concat_list"' EXIT
 
 missing=0
+total_expected_dur=0
 for season in Winter Spring Summer Autumn; do
     for mvt in 1 2 3; do
         mvt_dir="$year_dir/$season/Mvt$mvt/montage"
@@ -41,11 +42,14 @@ for season in Winter Spring Summer Autumn; do
             echo "WARNING: missing montage for $season Mvt$mvt ($mvt_dir)"
             missing=$((missing + 1))
         else
-            echo "  $season Mvt$mvt → $(basename "$f")"
+            d=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$f")
+            total_expected_dur=$(echo "scale=3; $total_expected_dur + $d" | bc)
+            echo "  $season Mvt$mvt → $(basename "$f")  (${d}s)"
             printf "file '%s'\n" "$f" >> "$concat_list"
         fi
     done
 done
+echo "Expected total duration: ${total_expected_dur}s ($(echo "scale=1; $total_expected_dur/60" | bc) min)"
 
 found=$(wc -l < "$concat_list")
 echo "$found of 12 movements found  ($missing missing)"
@@ -63,14 +67,26 @@ fi
 output_file="$year_dir/${CAM_NAME}-${ASTRO_YEAR}.mp4"
 echo "Output: $output_file"
 
-ffmpeg -loglevel warning \
+if ! ffmpeg -loglevel warning \
     -f concat -safe 0 -i "$concat_list" \
-    -c copy -y "$output_file"
+    -c copy -y "$output_file"; then
+    "$SCRIPT_DIR/notify.sh" "FAILED: year-end join $CAM_NAME $ASTRO_YEAR" \
+        "ffmpeg concat failed — the 12 movement montages are still intact" || true
+    exit 1
+fi
 
 total_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$output_file")
 total_min=$(echo "scale=1; $total_dur / 60" | bc)
 echo "Done: $output_file  (${total_min} min)"
 
+# Sanity-check actual vs expected duration
+dur_drift=$(echo "scale=3; $total_dur - $total_expected_dur" | bc | sed 's/^-//')
+if awk "BEGIN{exit !($dur_drift > 2.0)}"; then
+    echo "WARNING: output ${total_dur}s differs from expected ${total_expected_dur}s by ${dur_drift}s"
+    "$SCRIPT_DIR/notify.sh" "WARNING: year-end duration drift $CAM_NAME $ASTRO_YEAR" \
+        "Output ${total_dur}s vs expected ${total_expected_dur}s (drift ${dur_drift}s)" || true
+fi
+
 # ── Notify ────────────────────────────────────────────────────────────────────
 "$SCRIPT_DIR/notify.sh" \
     "Four Seasons $ASTRO_YEAR complete" \