change period format

src/lib/utils/time.js

@@ -1,36 +1,7 @@
 export default {
   getPeriod (start, end) {
-    let diff = end.getTime() - start.getTime()
-    let result = ''
-
-    const days = Math.floor(diff / (1000 * 60 * 60 * 24))
-    diff -= days * (1000 * 60 * 60 * 24)
-    if (days) {
-      result += days + ' d '
-    }
-
-    const hours = Math.floor(diff / (1000 * 60 * 60))
-    diff -= hours * (1000 * 60 * 60)
-    if (hours) {
-      result += hours + ' h '
-    }
-
-    const mins = Math.floor(diff / (1000 * 60))
-    diff -= mins * (1000 * 60)
-    if (mins) {
-      result += mins + ' m '
-    }
-
-    const seconds = Math.floor(diff / (1000))
-    diff -= seconds * (1000)
-    if (seconds) {
-      result += seconds + ' s '
-    }
-
-    if (diff) {
-      result += diff + ' ms '
-    }
-
-    return result.replace(/\s$/, '')
+    const diff = end.getTime() - start.getTime()
+    const seconds = diff / 1000
+    return seconds.toFixed(3) + 's'
   }
 }