change code structure

src/lib/utils/time.js

@@ -0,0 +1,36 @@
+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$/, '')
+  }
+}