Fix the time container whitespace issue (Hacker0x01#1717)

Author: PaulRBerg

src/time.jsx

@@ -43,6 +43,10 @@ export default class Time extends React.Component {
     );
   };
 
+  state = {
+    height: null
+  }
+
   componentDidMount() {
     // code to ensure selected time will always be in focus within time window when it first appears
     this.list.scrollTop = Time.calcCenterPosition(
@@ -51,6 +55,11 @@ export default class Time extends React.Component {
         : this.list.clientHeight,
       this.centerLi
     );
+    if (this.props.monthRef && this.header) {
+      this.setState({
+        height: this.props.monthRef.clientHeight - this.header.clientHeight
+      });
+    }
   }
 
   handleClick = time => {
@@ -143,10 +152,7 @@ export default class Time extends React.Component {
   };
 
   render() {
-    let height = null;
-    if (this.props.monthRef && this.header) {
-      height = this.props.monthRef.clientHeight - this.header.clientHeight;
-    }
+    const { height } = this.state;
 
     return (
       <div