Test breaks when run in a different timezone

spec/chatbox.js

@@ -961,6 +961,7 @@
                         null, ['rosterGroupsFetched'], {},
                         function (done, _converse) {
 
+
                     test_utils.createContacts(_converse, 'current');
                     test_utils.openControlBox();
                     test_utils.openContactsPanel(_converse);
@@ -1001,7 +1002,7 @@
 
                         msg = $msg({'id': 'aeb214', 'to': _converse.bare_jid})
                             .c('forwarded', {'xmlns': 'urn:xmpp:forward:0'})
-                                .c('delay', {'xmlns': 'urn:xmpp:delay', 'stamp':'2017-12-31T23:08:25Z'}).up()
+                                .c('delay', {'xmlns': 'urn:xmpp:delay', 'stamp':'2017-12-31T22:08:25Z'}).up()
                                 .c('message', {
                                     'xmlns': 'jabber:client',
                                     'to': _converse.bare_jid,
@@ -1049,7 +1050,7 @@
 
                         msg = $msg({'id': 'aeb218', 'to': _converse.bare_jid})
                             .c('forwarded', {'xmlns': 'urn:xmpp:forward:0'})
-                                .c('delay', {'xmlns': 'urn:xmpp:delay', 'stamp':'2018-01-02T23:28:23Z'}).up()
+                                .c('delay', {'xmlns': 'urn:xmpp:delay', 'stamp':'2018-01-02T22:28:23Z'}).up()
                                 .c('message', {
                                     'xmlns': 'jabber:client',
                                     'to': _converse.bare_jid,
@@ -1090,14 +1091,16 @@
                         var $time = $chat_content.find('time');
                         expect($time.length).toEqual(4);
                         $time = $chat_content.find('time:first');
-                        expect($time.data('isodate')).toEqual('2017-12-31T00:00:00+00:00');
+                        expect($time.data('isodate')).toEqual(moment('2017-12-31T00:00:00').format());
+                        expect($time.text()).toEqual('Sunday Dec 31st 2017')
 
                         expect($time[0].nextElementSibling.querySelector('.chat-msg-content').textContent).toBe('Older message');
                         var $el = $chat_content.find('.chat-message:first').find('.chat-msg-content')
                         expect($el.text()).toEqual('Older message');
 
                         $time = $chat_content.find('time:eq(1)');
-                        expect($time.data('isodate')).toEqual('2018-01-01T00:00:00+00:00');
+                        expect($time.data('isodate')).toEqual(moment('2018-01-01T00:00:00').format());
+                        expect($time.text()).toEqual("Monday Jan 1st 2018");
                         expect($time[0].nextElementSibling.querySelector('.chat-msg-content').textContent).toBe('Inbetween message');
                         $el = $chat_content.find('.chat-message:eq(1)');
                         expect($el.find('.chat-msg-content').text()).toEqual('Inbetween message');
@@ -1106,7 +1109,8 @@
                         expect($el.find('.chat-msg-content').text()).toEqual('another inbetween message');
 
                         $time = $chat_content.find('time:nth(2)');
-                        expect($time.data('isodate')).toEqual('2018-01-02T00:00:00+00:00');
+                        expect($time.data('isodate')).toEqual(moment('2018-01-02T00:00:00').format());
+                        expect($time.text()).toEqual("Tuesday Jan 2nd 2018");
                         expect($time[0].nextElementSibling.querySelector('.chat-msg-content').textContent).toBe('An earlier message on the next day');
                         $el = $chat_content.find('.chat-message:eq(3)');
                         expect($el.find('.chat-msg-content').text()).toEqual('An earlier message on the next day');