diff --git a/cache.go b/cache.go
index 1d7fa31..463a91e 100644
--- a/cache.go
+++ b/cache.go
@@ -56,7 +56,7 @@ func cacheMiddleware(next http.Handler) http.Handler {
 			}
 			if ifModifiedSinceHeader := r.Header.Get("If-Modified-Since"); ifModifiedSinceHeader != "" {
 				t, err := dateparse.ParseAny(ifModifiedSinceHeader)
-				if err == nil && t.Unix() >= cache.creationTime {
+				if err == nil && t.After(cache.creationTime) {
 					// send 304
 					w.WriteHeader(http.StatusNotModified)
 					return
@@ -80,12 +80,10 @@ func cacheKey(r *http.Request) string {
 func setCacheHeaders(w http.ResponseWriter, cache *cacheItem) {
 	w.Header().Del(cacheInternalExpirationHeader)
 	w.Header().Set("ETag", cache.hash)
-	w.Header().Set("Last-Modified", time.Unix(cache.creationTime, 0).UTC().Format(http.TimeFormat))
+	w.Header().Set("Last-Modified", cache.creationTime.UTC().Format(http.TimeFormat))
 	if w.Header().Get("Cache-Control") == "" {
 		if cache.expiration != 0 {
-			expiresIn := cache.creationTime + int64(cache.expiration) - time.Now().Unix()
-			// Set expires time
-			w.Header().Set("Cache-Control", fmt.Sprintf("public,max-age=%d,stale-while-revalidate=%d", expiresIn, cache.expiration))
+			w.Header().Set("Cache-Control", fmt.Sprintf("public,max-age=%d,stale-while-revalidate=%d", cache.expiration, cache.expiration))
 		} else {
 			w.Header().Set("Cache-Control", fmt.Sprintf("public,max-age=%d,s-max-age=%d,stale-while-revalidate=%d", appConfig.Cache.Expiration, appConfig.Cache.Expiration/3, appConfig.Cache.Expiration))
 		}
@@ -94,7 +92,7 @@ func setCacheHeaders(w http.ResponseWriter, cache *cacheItem) {
 
 type cacheItem struct {
 	expiration   int
-	creationTime int64
+	creationTime time.Time
 	hash         string
 	code         int
 	header       http.Header
@@ -103,7 +101,7 @@ type cacheItem struct {
 
 func (c *cacheItem) expired() bool {
 	if c.expiration != 0 {
-		return c.creationTime < time.Now().Unix()-int64(c.expiration)
+		return time.Now().After(c.creationTime.Add(time.Duration(c.expiration) * time.Second))
 	}
 	return false
 }
@@ -127,7 +125,7 @@ func getCache(key string, next http.Handler, r *http.Request) (item *cacheItem)
 		exp, _ := strconv.Atoi(result.Header.Get(cacheInternalExpirationHeader))
 		item = &cacheItem{
 			expiration:   exp,
-			creationTime: time.Now().Unix(),
+			creationTime: time.Now(),
 			hash:         hash,
 			code:         result.StatusCode,
 			header:       result.Header,
diff --git a/go.mod b/go.mod
index f48e1a7..19a6159 100644
--- a/go.mod
+++ b/go.mod
@@ -58,7 +58,7 @@ require (
 	golang.org/x/mod v0.4.0 // indirect
 	golang.org/x/net v0.0.0-20201224014010-6772e930b67b // indirect
 	golang.org/x/sync v0.0.0-20201207232520-09787c993a3a
-	golang.org/x/sys v0.0.0-20210108172913-0df2131ae363 // indirect
+	golang.org/x/sys v0.0.0-20210110051926-789bb1bd4061 // indirect
 	golang.org/x/term v0.0.0-20201210144234-2321bbc49cbf // indirect
 	golang.org/x/text v0.3.5 // indirect
 	golang.org/x/tools v0.0.0-20210108195828-e2f9c7f1fc8e // indirect
diff --git a/go.sum b/go.sum
index be1c336..4443e3f 100644
--- a/go.sum
+++ b/go.sum
@@ -454,8 +454,8 @@ golang.org/x/sys v0.0.0-20200724161237-0e2f3a69832c h1:UIcGWL6/wpCfyGuJnRFJRurA+
 golang.org/x/sys v0.0.0-20200724161237-0e2f3a69832c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210108172913-0df2131ae363 h1:wHn06sgWHMO1VsQ8F+KzDJx/JzqfsNLnc+oEi07qD7s=
-golang.org/x/sys v0.0.0-20210108172913-0df2131ae363/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210110051926-789bb1bd4061 h1:DQmQoKxQWtyybCtX/3dIuDBcAhFszqq8YiNeS6sNu1c=
+golang.org/x/sys v0.0.0-20210110051926-789bb1bd4061/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221 h1:/ZHdbVpdR/jk3g30/d4yUL0JU9kksj8+F/bnQUVLGDM=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=