MAGETWO-51629: Incorrect current time in date pickers

- fix for bamboo unit test

Author: iivashchenko

app/code/Magento/Backend/view/adminhtml/templates/page/js/calendar.phtml

@@ -50,7 +50,7 @@ require([
             showTime: false,
             showHour: false,
             showMinute: false,
-            serverTimezoneOffset: <?php echo (int) $block->getTimezoneOffsetSeconds(); ?>,
+            serverTimezoneSeconds: <?php echo (int) $block->getStoreTimestamp(); ?>,
             yearRange: '<?php /* @escapeNotVerified */ echo $block->getYearRange() ?>'
         }
     });

lib/web/mage/calendar.js

@@ -323,11 +323,10 @@
             // Get local time in ms
             var ms = Date.now();
 
-            // Adjust milliseconds according to store timezone offset
-            // Mind the GMT zero offset
-            if (typeof this.options.serverTimezoneOffset !== 'undefined') {                
-                // Make UTC time and add store timezone offset in seconds
-                ms += (new Date().getTimezoneOffset() * 60 * 1000) + this.options.serverTimezoneOffset * 1000;
+            // Use store timestamp based on store timezone settings
+            if (typeof this.options.serverTimezoneSeconds !== 'undefined') {
+                //Adjust milliseconds according to client local timezone offset
+                ms = (this.options.serverTimezoneSeconds + new Date().getTimezoneOffset() * 60) * 1000;
             }
 
             return new Date(ms);