Answered Server update gives error on Ditto : strftime(): Invalid date.timezone value

ErrorType[num] : 	WARNING[2]
File : 	/home/xxx/domains/xxx.nl/public_html/assets/snippets/ditto/classes/ditto.class.inc.php
Line : 	314
Source : 	$placeholders['date'] = strftime($dateFormat,$timestamp);
Basic info
REQUEST_URI : 	http://www.xxx.nl/sitemap.xml
Resource : 	[2]Sitemap xml
Current Snippet : 	Ditto
Current Plugin : 	phx(OnParseDocument)
Referer : 	
User Agent : 	Mozilla/5.0 (Windows NT 6.1; rv:27.0) Gecko/20100101 Firefox/27.0
IP : 	80.101.162.117
Benchmarks
MySQL : 	0.0018 s (5 Requests)
PHP : 	0.0201 s
Total : 	0.0219 s
Memory : 	2.2542724609375 mb

Backtrace
1	DocumentParser->executeParser()
index.php on line 144
2	DocumentParser->prepareResponse()
manager/includes/document.parser.class.inc.php on line 1621
3	DocumentParser->parseDocumentSource()
manager/includes/document.parser.class.inc.php on line 1711
4	DocumentParser->invokeEvent()
manager/includes/document.parser.class.inc.php on line 1487
5	DocumentParser->evalPlugin()
manager/includes/document.parser.class.inc.php on line 3393
6	eval()
manager/includes/document.parser.class.inc.php on line 1006
7	PHxParser->OnParseDocument()
manager/includes/document.parser.class.inc.php(1006) : eval()'d code on line 9
8	PHxParser->Parse()
assets/plugins/phx/phx.parser.class.inc.php on line 49
9	PHxParser->ParseValues()
assets/plugins/phx/phx.parser.class.inc.php on line 64
10	PHxParser->ParseValues()
assets/plugins/phx/phx.parser.class.inc.php on line 199
11	DocumentParser->evalSnippets()
assets/plugins/phx/phx.parser.class.inc.php on line 131
12	DocumentParser->_get_snip_result()
manager/includes/document.parser.class.inc.php on line 1091
13	DocumentParser->evalSnippet()
manager/includes/document.parser.class.inc.php on line 1178
14	eval()
manager/includes/document.parser.class.inc.php on line 1039
15	require()
manager/includes/document.parser.class.inc.php(1039) : eval()'d code on line 1
16	ditto->render()
assets/snippets/ditto/snippet.ditto.php on line 1032
17	strftime()
assets/snippets/ditto/classes/ditto.class.inc.php on line 314