Add m alias for minute duration literal

[felixbarny]

Allows ES|QL queries like this:

FROM logs-* | WHERE @timestamp > now() - 1m

There's a potential ambiguity with month but m is commonly used in other query languages to mean minutes so I think that's essentially common practice.

Today, we don't support m and a query would fail with Unexpected temporal unit: 'm'. So this change is not breaking existing behavior.

Closes #135552

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)

[github-actions]

🔍 Preview links for changed docs

• docs/reference/query-languages/esql/esql-time-spans.md

[github-actions]

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[elasticsearchmachine]

Hi @felixbarny, I've created a changelog YAML for you.

[felixbarny]

Note that the DATE_DIFF function treats m as month, not minute, so this would introduce a small inconsistency. Given the prevalence of m meaning minutes in other query languages, and the fact that duration literals and date_diff support different values, I think that small consistency is probably fine.

However, we can think about de-emphasizing or deprecating m to mean month in date_diff. For example, we could remove it from the documentation while still supporting it.

[felixbarny]

See also this note from the date_diff docs:

Note that while there is an overlap between the function’s supported units and ES|QL’s supported time span literals, these sets are distinct and not interchangeable.

Seems like it's fine that the date_diff and time span/duration units differ.

[costin]

LGTM, adding @bpintea since he's been working in this area and for awareness of the m usage in DATE_DIFF.

[costin]

👍

[bpintea]

Except for a comment, it LGTM.

m isn't quite unambiguous, unfortunately. Worse off, we have a DATE_DIFF function that uses its own set of units and uses m for month, inline with other SQL implementations of the similar function, like MS SQL. (And the conflict/confusion shows already, like in #136426, despite our docs clarification). But I guess we can assume that minute has a higher usage generally and prioritise it.