diff --git a/main.go b/main.go
index c78fdb5..cb25f46 100644
--- a/main.go
+++ b/main.go
@@ -1,9 +1,10 @@
 package main
 
 import (
-	"flag"
 	"os"
 	"path/filepath"
+	"regexp"
+	"strconv"
 	"strings"
 	"time"
 
@@ -12,11 +13,17 @@ import (
 )
 
 type Config struct {
-	WorkDir     string
-	ScanSeconds int
-	Patterns    []string
+	WorkDir      string
+	Patterns     []string
+	ScanInterval time.Duration
 }
 
+var (
+	timeUnits  = map[string]int64{"ms": 1, "s": 1000, "m": 60_000, "h": 3_600_000, "d": 86_400_000, "M": 2_592_000_000, "y": 31_536_000_000}
+	valueRegex = regexp.MustCompile(`\d+`)
+	unitRegex  = regexp.MustCompile(`[a-zA-Z]+`)
+)
+
 func getenv(key, def string) string {
 	if v, ok := os.LookupEnv(key); ok {
 		return v
@@ -24,51 +31,77 @@ func getenv(key, def string) string {
 	return def
 }
 
-func loadConfig() Config {
-	flagWDir := flag.String("wd", "", "working directory")
-	flagScan := flag.Int("scan", 60, "scan interval in seconds")
-	logger.InitFlag()
-	flag.Parse()
-
-	workdir := filepath.Clean(*flagWDir)
-	if pfx := strings.TrimSpace(getenv("PATH_PREFIX", "")); pfx != "" {
-		workdir = filepath.Join(workdir, pfx)
+func parseDurationMS(expr string) int64 {
+	expr = strings.TrimSpace(expr)
+	if expr == "" {
+		return 0
 	}
-	workdir = filepath.ToSlash(workdir)
+	var total int64
+	for _, p := range strings.Split(expr, "_") {
+		p = strings.TrimSpace(p)
+		if p == "" {
+			continue
+		}
+		v := valueRegex.FindString(p)
+		u := unitRegex.FindString(p)
+		if v == "" || u == "" {
+			logger.Warning("Invalid duration part: %q", p)
+			continue
+		}
+		unit, ok := timeUnits[u]
+		if !ok {
+			logger.Warning("Invalid duration unit: %q", u)
+			continue
+		}
+		n, err := strconv.ParseInt(v, 10, 64)
+		if err != nil {
+			logger.Warning("Invalid duration value: %q: %v", v, err)
+			continue
+		}
+		total += n * unit
+	}
+	return total
+}
 
-	// Gather patterns: args + FORBIDDEN env (comma-separated)
-	patterns := []string{}
-	patterns = append(patterns, flag.Args()...)
+func loadConfig() Config {
+	// logger.InitFlag() is optional if you don't use CLI flags to set log level,
+	// but it is safe to call to honor standard logger flags if provided.
+	logger.InitFlag()
+
+	workdir := filepath.ToSlash(strings.TrimSpace(getenv("WORKDIR", "/tmp")))
+	if pfx := strings.TrimSpace(getenv("PATH_PREFIX", "")); pfx != "" {
+		workdir = filepath.ToSlash(filepath.Join(workdir, pfx))
+	}
+
+	// Patterns from FORBIDDEN (comma-separated). Relative to WorkDir.
+	var patterns []string
 	if env := strings.TrimSpace(getenv("FORBIDDEN", "")); env != "" {
 		for _, p := range strings.Split(env, ",") {
 			p = strings.TrimSpace(p)
 			if p != "" {
-				patterns = append(patterns, p)
+				patterns = append(patterns, filepath.ToSlash(p))
 			}
 		}
 	}
 
-	// Normalize patterns to slash style; patterns are relative to workdir
-	for i := range patterns {
-		patterns[i] = filepath.ToSlash(strings.TrimSpace(patterns[i]))
-	}
+	interval := time.Duration(parseDurationMS(getenv("SCAN_INTERVAL", "60s"))) * time.Millisecond
 
 	logger.Info("Config:")
-	logger.Info("  WorkDir: %s", workdir)
-	logger.Info("  ScanSeconds: %d", *flagScan)
-	logger.Info("  Patterns: %v", patterns)
+	logger.Info("  WORKDIR: %s", workdir)
+	logger.Info("  PATH_PREFIX: %s", getenv("PATH_PREFIX", ""))
+	logger.Info("  FORBIDDEN: %v", patterns)
+	logger.Info("  SCAN_INTERVAL(ms): %d", interval.Milliseconds())
 
 	return Config{
-		WorkDir:     workdir,
-		ScanSeconds: *flagScan,
-		Patterns:    patterns,
+		WorkDir:      workdir,
+		Patterns:     patterns,
+		ScanInterval: interval,
 	}
 }
 
 func deleteMatches(cfg Config) {
 	log := logger.Default.WithPrefix("deleteMatches")
 
-	// Ensure workdir exists
 	if cfg.WorkDir == "" {
 		log.Error("WorkDir is empty")
 		return
@@ -82,7 +115,6 @@ func deleteMatches(cfg Config) {
 		if pat == "" {
 			continue
 		}
-		// Use doublestar.Glob against the workdir FS; it returns relative paths
 		matches, err := doublestar.Glob(os.DirFS(cfg.WorkDir), pat)
 		if err != nil {
 			log.Error("glob %q: %v", pat, err)
@@ -94,9 +126,7 @@ func deleteMatches(cfg Config) {
 		}
 
 		for _, rel := range matches {
-			full := filepath.Join(cfg.WorkDir, rel)
-			full = filepath.Clean(full)
-
+			full := filepath.Clean(filepath.Join(cfg.WorkDir, rel))
 			info, err := os.Stat(full)
 			if err != nil {
 				log.Warning("stat %s: %v", full, err)
@@ -117,18 +147,23 @@ func deleteMatches(cfg Config) {
 	}
 }
 
+func doRun(cfg Config) {
+	deleteMatches(cfg)
+}
+
 func main() {
 	cfg := loadConfig()
 	logger.Info("Starting forbidden cleaner")
+	doRun(cfg)
 
-	// Run immediately, then on interval
-	deleteMatches(cfg)
+	t := time.NewTicker(cfg.ScanInterval)
+	defer t.Stop()
 
-	ticker := time.NewTicker(time.Duration(cfg.ScanSeconds) * time.Second)
-	defer ticker.Stop()
 	for {
-		ts := <-ticker.C
-		logger.Info("Tick %d", ts.UnixMilli())
-		deleteMatches(cfg)
+		select {
+		case ts := <-t.C:
+			logger.Info("Tick %d", ts.UnixMilli())
+			doRun(cfg)
+		}
 	}
 }