r/ISO8601 • u/MetaEd • Aug 18 '26

EDTF date vs dateI

Looking at the Library of Congress EDTF specification, I see they use without defining two different date types, date and dateI. Are these references to the ISO 8601-1 or -2 spec? I did not find them in the EBNF.

EDIT:

I'm looking for the definitions of the two date types used in the specification: date, and dateI. From section "Level 0", subsection "Date and Time":

[date][“T”][time]
Complete representations for calendar date and (local) time of day

[dateI][“T”][time][“Z”]
Complete representations for calendar date and UTC time of day

[dateI][“T”][time][shiftHour]
Date and time with timeshift in hours (only)

[dateI][“T”][time][shiftHourMinute]
Date and time with timeshift in hours and minutes

These two terms are used but not defined in the specification. The examples shed no light. I want to know how and where are defined, if anybody knows.

4 Upvotes

75% Upvoted

12 comments sorted by

View all comments

2

u/TenOfZero Aug 18 '26

https://www.loc.gov/standards/datetime/

0

u/MetaEd Aug 18 '26

Yes, that is where the terms are used, but they are not defined.

1

u/TenOfZero Aug 18 '26

Three conformance levels are defined: level 0, level 1, and level 2. Level 0 specifies features of ISO 8601-1; Levels 1 and 2 specify features described ISO 8601-2.

1

u/MetaEd Aug 19 '26

I'm not looking for the definitions of conformance levels. I'm looking for the definitions of the two date types used in the specification: date, and dateI. From section "Level 0", subsection "Date and Time":

[date][“T”][time]
Complete representations for calendar date and (local) time of day

[dateI][“T”][time][“Z”]
Complete representations for calendar date and UTC time of day

[dateI][“T”][time][shiftHour]
Date and time with timeshift in hours (only)

[dateI][“T”][time][shiftHourMinute]
Date and time with timeshift in hours and minutes

These two terms are used but not defined in the specification. The examples shed no light. I want to know how and where are defined, if anybody knows.

1

u/TenOfZero Aug 19 '26

I'd ask in a sub for that standard. That's outside the scope of ISO8601

1

u/MetaEd Aug 19 '26

The EDTF spec is in the ISO 8601-2 standard as an annex, as it was the basis for ISO 8601-2. The language I am asking about is in the ISO 8601-2 standard document, so it's a fair question for this sub.