deps: update icu to 78.1

[nodejs-github-bot]

This is an automated update of icu to 78.1.

[nodejs-github-bot]

Review requested:

• [ ] @nodejs/security-wg

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/69987/

[targos]

/cc @nodejs/i18n-api This output change is weird: https://ci.nodejs.org/job/node-test-commit-linuxone/nodes=rhel9-s390x/52175/testReport/junit/(root)/parallel/test_datetime_change_notify/

  AssertionError [ERR_ASSERTION]: The input did not match the regular expression /Irish Standard Time|Greenwich Mean Time/. Input:

  '11/1/2025, 10:49:12 AM GMT+00:00'

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 88.54%. Comparing base (7fd3688) to head (c5eb768). :warning: Report is 38 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #60523      +/-   ##
==========================================
- Coverage   88.56%   88.54%   -0.02%     
==========================================
  Files         703      703              
  Lines      208254   208239      -15     
  Branches    40156    40153       -3     
==========================================
- Hits       184430   184394      -36     
- Misses      15828    15866      +38     
+ Partials     7996     7979      -17     

see 63 files with indirect coverage changes

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[richardlau]

/cc @nodejs/i18n-api This output change is weird: https://ci.nodejs.org/job/node-test-commit-linuxone/nodes=rhel9-s390x/52175/testReport/junit/(root)/parallel/test_datetime_change_notify/

  AssertionError [ERR_ASSERTION]: The input did not match the regular expression /Irish Standard Time|Greenwich Mean Time/. Input:

  '11/1/2025, 10:49:12 AM GMT+00:00'

FWIW it looks like a change when DST is not in effect (no longer outputs Greenwich Mean time):

> process.env.TZ='Europe/Dublin'
'Europe/Dublin'
> new Date('2025/10/01').toLocaleString('en-US', { timeZoneName: 'long' })
'10/1/2025, 12:00:00 AM Irish Standard Time'
> new Date('2025/11/01').toLocaleString('en-US', { timeZoneName: 'long' })
'11/1/2025, 12:00:00 AM GMT+00:00'
>

[targos]

/cc @srl295

The new output looks more like what we should get with timeZoneName: "longOffset"

[targos]

I pushed an update to the test, but still not convinced that it's an expected change.

[srl295]

I pushed an update to the test, but still not convinced that it's an expected change.

Can you file a CLDR issue ?

[targos]

CLDR bug: https://unicode-org.atlassian.net/browse/CLDR-19136

[srl295]

CLDR bug: https://unicode-org.atlassian.net/browse/CLDR-19136

it's now an ICU bug, precipitated by a CLDR change.

[targos]

https://unicode-org.atlassian.net/browse/ICU-23278

Let's wait for 78.2 or 79.1.

[richardlau]

https://unicode-org.atlassian.net/browse/ICU-23278

Let's wait for 78.2 or 79.1.

SGTM. FWIW https://github.com/unicode-org/icu/pull/3784 updates icu4c/source/data/misc/metaZones.txt which we don't check into the Node.js source tree so we'd have to regenerate deps/icu-small/source/data/in/icudt78l.dat.bz2 (i.e. we cannot use the floating patch method in https://github.com/nodejs/node/blob/main/doc/contributing/maintaining/maintaining-icu.md#floating-patches-to-icu).

Having said that, we do regenerate the dat file to pick up timezone updates (there's one coming (2025c) from https://github.com/unicode-org/icu-data/pull/46).