momentjs Library causing timezone shifting failure in date form element Ui Component

[henriquebis2bis]

Preconditions and environment

• Magento any version
• Set the store timezone to America/Sao_Paulo for example

Steps to reproduce

1. Set store timezone to America/Sao_Paulo
2. Create date formElement in any ui component, example in category_form.xml:

3. Create the category attributes throught data patch, example:
   `$eavSetup->addAttribute(
   Category::ENTITY,
   'promotion_start_date',
   [
   'type' => 'datetime',
   'label' => 'Data Início da Promoção',
   'input' => 'date',
   'required' => false,
   'sort_order' => 100,
   'global' => ScopedAttributeInterface::SCOPE_GLOBAL,
   'group' => 'PÁGINA DE PROMOÇÃO',
   'backend' => \Magento\Eav\Model\Entity\Attribute\Backend\Datetime::class,
   ]
   );

    $eavSetup->addAttribute(
        Category::ENTITY,
        'promotion_end_date',
        [
            'type' => 'datetime',
            'label' => 'Data Fim da Promoção',
            'input' => 'date',
            'required' => false,
            'sort_order' => 110,
            'global' => ScopedAttributeInterface::SCOPE_GLOBAL,
            'group' => 'PÁGINA DE PROMOÇÃO',
            'backend' => \Magento\Eav\Model\Entity\Attribute\Backend\Datetime::class,
        ]
    );`
   

4. Use magento 2 /rest/all/V1/categories/ API to set a date in this fields request example:
   { "category": { "id": {{categoryId}}, "custom_attributes": [ { "attribute_code": "promotion_start_date", "value": "2025-12-06 23:06:11" }, { "attribute_code": "promotion_end_date", "value": "2025-12-08 22:21:11" } ] } }

5. Check in the category changed form in the admin area that the time will be UTC-2 instead of UTC-3, Brazil doesn't have summer time changes anymore, so we are always UTC-3, the momentjs library is not updated towards this, and it has been a while since we had this change

Expected result

Have the frontend component be loaded to -3 hours from UTC

Actual result

The frontend component is being loaded -2 hours from UTC

Additional information

No response

Release note

No response

Triage and priority

• Severity: S0 - Affects critical data or functionality and leaves users without workaround.
• Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.

[m2-assistant]

Hi @henriquebis2bis. Thank you for your report.
To speed up processing of this issue, make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce.

• For more details, review the Magento Contributor Assistant documentation.
• Add a comment to assign the issue: @magento I am working on this
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