The definition "the Gregorian calendar is always used" seems a little weak also compared to the alternate interpretation in Part 4, section 3.17.4.1

Ref. to relevant date representation Part 4 3.17.4.1

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line 18 Part 4
section 2.16.5.72

Ed

Proposed Disposition of DIS 29500 Comment DK-0129 (Modified: 2007-12-08) Agreed, in fact, based on other responses the date-and-time formatting switches will be revised to include other calendars; accordingly, the following changes will be made in Part 4, §2.16.5.72, page 1,565, line 18: 2.16.5.72 TIME Description: Retrieves the current date and time. The Gregorian calendar is always used. By default, the date-and-time-formatting-switch used is implementation-defined. Similar Comments: FR-0309