[3] XPath and XQuery Functions and Operators 3.0 ( ( 版)) <http://www.w3.org/TR/xpath-functions-3/#lang-cal-place>
[4] XPath and XQuery Functions and Operators 3.1 () <https://www.w3.org/TR/2017/REC-xpath-functions-31-20170321/#lang-cal-place>
[1] XQuery 3.1: An XML Query Language () <https://www.w3.org/TR/2017/REC-xquery-31-20170321/#dt-default-calendar>
[2] XML Path Language (XPath) 3.1 () <https://www.w3.org/TR/2017/REC-xpath-31-20170321/#dt-default-calendar>
[5] 計算機システムにおける暦の指定も参照。