diff --git a/CLAUDE.md b/CLAUDE.md
index c31981c..66dc3f3 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -31,16 +31,12 @@ Key functions: `parse_time` (time spec → OnCalendar), `_write_unit_files` (sha
 
 ## Testing
 
-There are no automated tests. Test manually with systemd user timers:
 ```bash
-./systab -t "every 5 minutes" -c "echo test"
-./systab -S
-./systab -L
-./systab -P <id>
-./systab -R <id>
-./systab -C
+./test.sh
 ```
 
+Runs 44 tests against real systemd user timers covering job creation, status, logs, pause/resume, notifications, time format parsing, error cases, and cleanup. All test jobs are cleaned up automatically via trap.
+
 ## Notes
 
 - ShellCheck can be used for linting: `shellcheck systab`.
diff --git a/test.sh b/test.sh
new file mode 100755
index 0000000..a8e3155
--- /dev/null
+++ b/test.sh
@@ -0,0 +1,317 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SYSTAB="./systab"
+SYSTEMD_USER_DIR="${HOME}/.config/systemd/user"
+
+passed=0
+failed=0
+total=0
+
+# Colors (disabled if not a terminal)
+if [[ -t 1 ]]; then
+    GREEN=$'\033[32m' RED=$'\033[31m' BOLD=$'\033[1m' RESET=$'\033[0m'
+else
+    GREEN="" RED="" BOLD="" RESET=""
+fi
+
+# --- Helpers ---
+
+pass() {
+    echo "${GREEN}[PASS]${RESET} $1"
+    passed=$((passed + 1))
+    total=$((total + 1))
+}
+
+fail() {
+    echo "${RED}[FAIL]${RESET} $1 — $2"
+    failed=$((failed + 1))
+    total=$((total + 1))
+}
+
+# Run command, expect exit 0
+assert_success() {
+    local desc="$1"; shift
+    local output
+    if output=$("$@" 2>&1); then
+        _last_output="$output"
+        pass "$desc"
+    else
+        _last_output="$output"
+        fail "$desc" "expected exit 0, got $?"
+    fi
+}
+
+# Run command, expect non-zero exit
+assert_failure() {
+    local desc="$1"; shift
+    local output
+    if output=$("$@" 2>&1); then
+        _last_output="$output"
+        fail "$desc" "expected non-zero exit, got 0"
+    else
+        _last_output="$output"
+        pass "$desc"
+    fi
+}
+
+# Run command, check stdout contains string
+assert_output() {
+    local desc="$1" expected="$2"; shift 2
+    local output
+    if output=$("$@" 2>&1); then
+        _last_output="$output"
+        if [[ "$output" == *"$expected"* ]]; then
+            pass "$desc"
+        else
+            fail "$desc" "output missing \"$expected\""
+        fi
+    else
+        _last_output="$output"
+        fail "$desc" "command failed (exit $?)"
+    fi
+}
+
+# Check that $_last_output contains string
+assert_last_output_contains() {
+    local desc="$1" expected="$2"
+    if [[ "$_last_output" == *"$expected"* ]]; then
+        pass "$desc"
+    else
+        fail "$desc" "output missing \"$expected\""
+    fi
+}
+
+# Check file exists and contains pattern (grep -q)
+assert_file_contains() {
+    local desc="$1" file="$2" pattern="$3"
+    if [[ ! -f "$file" ]]; then
+        fail "$desc" "file not found: $file"
+    elif grep -q -e "$pattern" "$file"; then
+        pass "$desc"
+    else
+        fail "$desc" "pattern \"$pattern\" not in $file"
+    fi
+}
+
+# Extract job ID from "Job created: <id>" output
+extract_id() {
+    sed -n 's/^Job created: \([0-9a-f]\{6\}\)$/\1/p' <<< "$_last_output"
+}
+
+# Remove all systab_* unit files and reload
+cleanup() {
+    local had_units=false
+    for f in "$SYSTEMD_USER_DIR"/systab_*.service "$SYSTEMD_USER_DIR"/systab_*.timer; do
+        [[ -f "$f" ]] || continue
+        local unit
+        unit=$(basename "$f")
+        systemctl --user stop "$unit" 2>/dev/null || true
+        systemctl --user disable "$unit" 2>/dev/null || true
+        rm -f "$f"
+        had_units=true
+    done
+    if $had_units; then
+        systemctl --user daemon-reload 2>/dev/null || true
+    fi
+}
+
+# --- Setup ---
+
+_last_output=""
+trap cleanup EXIT
+cleanup
+
+echo "${BOLD}Running systab tests...${RESET}"
+echo ""
+
+# ============================================================
+# Job creation
+# ============================================================
+
+echo "${BOLD}--- Job creation ---${RESET}"
+
+assert_output "create recurring job" "Job created:" $SYSTAB -t "every 5 minutes" -c "echo test_recurring"
+id_recurring=$(extract_id)
+
+assert_output "create one-time job" "Job created:" $SYSTAB -t "in 30 minutes" -c "echo test_onetime"
+id_onetime=$(extract_id)
+
+if [[ -z "$id_recurring" || -z "$id_onetime" ]]; then
+    echo "FATAL: could not extract job IDs, aborting"
+    exit 1
+fi
+
+# ============================================================
+# Status
+# ============================================================
+
+echo ""
+echo "${BOLD}--- Status ---${RESET}"
+
+assert_output "show status all" "Managed Jobs Status" $SYSTAB -S
+assert_last_output_contains "status contains recurring job ID" "$id_recurring"
+assert_last_output_contains "status contains one-time job ID" "$id_onetime"
+
+assert_output "show status single job" "$id_recurring" $SYSTAB -S "$id_recurring"
+
+# ============================================================
+# Logs
+# ============================================================
+
+echo ""
+echo "${BOLD}--- Logs ---${RESET}"
+
+assert_output "view logs all" "Logs for" $SYSTAB -L
+assert_output "view logs single job" "$id_recurring" $SYSTAB -L "$id_recurring"
+
+# ============================================================
+# Pause / Resume
+# ============================================================
+
+echo ""
+echo "${BOLD}--- Pause / Resume ---${RESET}"
+
+assert_output "pause job" "Paused:" $SYSTAB -P "$id_recurring"
+
+assert_output "show paused state" "Disabled" $SYSTAB -S "$id_recurring"
+
+assert_output "pause already paused" "Already paused:" $SYSTAB -P "$id_recurring"
+
+assert_output "resume job" "Resumed:" $SYSTAB -R "$id_recurring"
+
+assert_output "resume already running" "Already running:" $SYSTAB -R "$id_recurring"
+
+# ============================================================
+# Notifications
+# ============================================================
+
+echo ""
+echo "${BOLD}--- Notifications ---${RESET}"
+
+assert_output "create with -i" "Job created:" $SYSTAB -t "every 10 minutes" -c "echo notify_test" -i
+id_notify=$(extract_id)
+assert_file_contains "-i service has ExecStopPost" \
+    "$SYSTEMD_USER_DIR/systab_${id_notify}.service" "^ExecStopPost="
+assert_file_contains "-i service has notify-send" \
+    "$SYSTEMD_USER_DIR/systab_${id_notify}.service" "notify-send"
+
+assert_output "create with -i -o" "Job created:" $SYSTAB -t "every 10 minutes" -c "echo output_test" -i -o
+id_output=$(extract_id)
+assert_file_contains "-i -o service has journalctl" \
+    "$SYSTEMD_USER_DIR/systab_${id_output}.service" "journalctl"
+assert_file_contains "-i -o service has %%s" \
+    "$SYSTEMD_USER_DIR/systab_${id_output}.service" "%%s"
+
+assert_output "create with -i -o 5" "Job created:" $SYSTAB -t "every 10 minutes" -c "echo output5_test" -i -o 5
+id_output5=$(extract_id)
+assert_file_contains "-i -o 5 service has -n 5" \
+    "$SYSTEMD_USER_DIR/systab_${id_output5}.service" "-n 5"
+
+# Email notification (only if sendmail/msmtp available)
+if command -v sendmail &>/dev/null || command -v msmtp &>/dev/null; then
+    assert_output "create with -m" "Job created:" $SYSTAB -t "every 10 minutes" -c "echo mail_test" -m test@example.com
+    id_mail=$(extract_id)
+    assert_file_contains "-m service has ExecStopPost" \
+        "$SYSTEMD_USER_DIR/systab_${id_mail}.service" "^ExecStopPost="
+
+    assert_output "create with -i -m" "Job created:" $SYSTAB -t "every 10 minutes" -c "echo both_test" -i -m test@example.com
+    id_both=$(extract_id)
+    local_count=$(grep -c "^ExecStopPost=" "$SYSTEMD_USER_DIR/systab_${id_both}.service")
+    if [[ "$local_count" -ge 2 ]]; then
+        pass "-i -m service has two ExecStopPost lines"
+    else
+        fail "-i -m service has two ExecStopPost lines" "found $local_count"
+    fi
+else
+    echo "  (skipping email notification tests — no sendmail/msmtp)"
+fi
+
+# ============================================================
+# Time format parsing
+# ============================================================
+
+echo ""
+echo "${BOLD}--- Time format parsing ---${RESET}"
+
+# Source parse_time from systab (we need the function)
+# We can call it by running systab in a subshell that only defines the function
+parse_time_test() {
+    local input="$1" expected="$2"
+    # Run parse_time via bash sourcing
+    local result
+    if result=$(bash -c '
+        source <(sed -n "/^parse_time()/,/^}/p" ./systab; sed -n "/^error()/,/^}/p" ./systab; sed -n "/^is_recurring()/,/^}/p" ./systab)
+        parse_time "$1"
+    ' _ "$input" 2>&1); then
+        if [[ "$result" == "$expected" ]]; then
+            pass "parse_time '$input' -> '$expected'"
+        else
+            fail "parse_time '$input'" "got '$result', expected '$expected'"
+        fi
+    else
+        fail "parse_time '$input'" "failed: $result"
+    fi
+}
+
+parse_time_test "every 5 minutes" "*:0/5"
+parse_time_test "every day at 2am" "*-*-* 02:00:00"
+parse_time_test "daily" "daily"
+parse_time_test "hourly" "hourly"
+parse_time_test "every monday at 9am" "Mon *-*-* 09:00:00"
+parse_time_test "*:0/15" "*:0/15"
+parse_time_test "every minute" "*:*"
+parse_time_test "every hour" "hourly"
+parse_time_test "weekly" "weekly"
+parse_time_test "monthly" "monthly"
+
+# "in 5 minutes" produces an absolute timestamp — just check it doesn't fail
+assert_success "parse_time 'in 5 minutes' succeeds" bash -c '
+    source <(sed -n "/^parse_time()/,/^}/p" ./systab; sed -n "/^error()/,/^}/p" ./systab)
+    parse_time "in 5 minutes"
+'
+
+# ============================================================
+# Error cases
+# ============================================================
+
+echo ""
+echo "${BOLD}--- Error cases ---${RESET}"
+
+assert_failure "missing -t" $SYSTAB -c "echo hello"
+assert_failure "-c and -f together" $SYSTAB -t "daily" -c "echo hello" -f /nonexistent
+assert_failure "invalid job ID for -P" $SYSTAB -P "zzzzzz"
+assert_failure "invalid job ID for -R" $SYSTAB -R "zzzzzz"
+
+# -o without -i or -m: should succeed (flag accepted, just no notification lines)
+assert_output "-o without -i/-m creates job" "Job created:" $SYSTAB -t "every 10 minutes" -c "echo bare_output" -o
+id_bare_o=$(extract_id)
+# Should have FLAGS comment but no ExecStopPost
+assert_file_contains "-o without -i/-m has FLAGS comment" \
+    "$SYSTEMD_USER_DIR/systab_${id_bare_o}.service" "SYSTAB_FLAGS=o"
+# Should NOT have ExecStopPost
+if grep -q "^ExecStopPost=" "$SYSTEMD_USER_DIR/systab_${id_bare_o}.service"; then
+    fail "-o without -i/-m has no ExecStopPost" "found ExecStopPost"
+else
+    pass "-o without -i/-m has no ExecStopPost"
+fi
+
+# ============================================================
+# Clean
+# ============================================================
+
+echo ""
+echo "${BOLD}--- Clean ---${RESET}"
+
+# No elapsed one-time jobs (our one-time is still waiting)
+assert_output "clean with no elapsed jobs" "No completed" $SYSTAB -C < /dev/null
+
+# ============================================================
+# Summary
+# ============================================================
+
+echo ""
+echo "---"
+echo "${BOLD}${total} tests: ${GREEN}${passed} passed${RESET}, ${RED}${failed} failed${RESET}"
+
+[[ $failed -eq 0 ]]