Present User Selected Time and Now in UTC format (#161)

* switch NOW from local time to UTC time to avoid empty screen

* address comment

* address comments

pkg/sloop/webserver/webfiles/index.html

@@ -36,13 +36,12 @@ For full license text, see LICENSE.txt file in the repo root or https://opensour
             <select name="query" id="filterquery" hidden="true"> </select>
             <!-- <br><br> -->
 
-            <!-- Temporarily disable Endtime
-            <label for="selectedEndTime">End Time</label><br/>
+            <label for="selectedEndTime">End Time:</label><br/>
             <div>
                 <input type="datetime-local" step="1" id="selectedEndTime" name="selectedEndTime" />
                 <input type="button" value="Now" name="now" id="now">
             </div><br>
-            -->
+
 
             <label for="filterlookback">Look Back Range:</label><br/>
             <select name="lookback" id="filterlookback">

pkg/sloop/webserver/webfiles/sloop_ui.js

@@ -519,26 +519,27 @@ function showDetailedTooltip(d, event, parent) {
 $(document).ready(function() {
     //Set max allowed selected date/time to now
     const now = new Date();
-    var iso = now.toISOString();
+    var utcNow = new Date(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate(), now.getUTCHours(), now.getUTCMinutes(), now.getUTCSeconds());
+    var iso = utcNow.toISOString();
     var maxDate = iso.substring(0,iso.length-5);
     elem = document.getElementById("selectedEndTime");
     elem.value = maxDate;
     elem.max = maxDate;
 
     //Display user selected end time on ui after click submit button or refresh the page
-    var userDate = new Date();
+    //Set page default to UTC time on first loading
+    var userDate = utcNow;
     // check if selected end time happened within 3 seconds
     if (sessionStorage.getItem('setSelectedEndTime') !== null
         && ! Date.parse(sessionStorage.getItem('setSelectedEndTime')) < new Date(userDate.getTime() - 3000)){
         userDate = new Date(sessionStorage.getItem('selectedEndTime'));
     }
-    userDate.setMinutes(now.getMinutes() - now.getTimezoneOffset());
+    userDate.setMinutes(userDate.getMinutes() - userDate.getTimezoneOffset());
     userDate.setMilliseconds(null);
     document.getElementById('selectedEndTime').value = userDate.toISOString().slice(0, -1);
 
     $('#now').click(function(){
         const resetNow = new Date();
-        resetNow.setMinutes(resetNow.getMinutes() - resetNow.getTimezoneOffset());
         resetNow.setMilliseconds(null);
         document.getElementById('selectedEndTime').value = resetNow.toISOString().slice(0, -1);
         sessionStorage.removeItem('selectedEndTime');