isSameOrAfter() returns incorrect results when used with tz('UTC', true) and time comparison

[hamzanz]

Describe the bug
Description:
When comparing times using isSameOrAfter() in combination with tz('UTC', true), two issues occur:

tz('UTC', true) with keepLocalTime shifts the displayed times despite the keepLocalTime: true parameter
isSameOrAfter() returns incorrect comparison results when used with these timezone-converted times

Steps to Reproduce:

// Setup
import dayjs from 'dayjs';
import utc from 'dayjs/plugin/utc';
import timezone from 'dayjs/plugin/timezone';
import isSameOrAfter from 'dayjs/plugin/isSameOrAfter';

dayjs.extend(utc);
dayjs.extend(timezone);
dayjs.extend(isSameOrAfter);

// Test function
function compareTimeTest(targetTime: string, referenceTime: string) {
  const targetDateTime = dayjs(`1970-01-01 ${targetTime}`).tz('UTC', true);
  const referenceDateTime = dayjs(`1970-01-01 ${referenceTime}`).tz('UTC', true);

  console.log('Input times:', { targetTime, referenceTime });
  console.log('Dayjs string representation:', {
    target: targetDateTime.toString(),
    reference: referenceDateTime.toString()
  });
  console.log('Formatted times:', {
    targetTime: targetDateTime.format('HH:mm:ss'),
    referenceTime: referenceDateTime.format('HH:mm:ss')
  });
  console.log('Timestamp values:', {
    targetValue: targetDateTime.valueOf(),
    referenceValue: referenceDateTime.valueOf()
  });
  console.log('Comparisons:', {
    valueComparison: targetDateTime.valueOf() >= referenceDateTime.valueOf(),
    isSameOrAfter: targetDateTime.isSameOrAfter(referenceDateTime)
  });
}

// Run test
compareTimeTest('07:00:00', '08:00:00');

Current Output:

Input times: {
  targetTime: '07:00:00',
  referenceTime: '08:00:00'
}
Dayjs string representation: {
  target: 'Thu, 01 Jan 1970 07:00:00 GMT',
  reference: 'Thu, 01 Jan 1970 08:00:00 GMT'
}
Formatted times: {
  targetTime: '12:00:00',
  referenceTime: '13:00:00'
}
Timestamp values: {
  targetValue: 25200000,
  referenceValue: 28800000
}
Comparisons: {
  valueComparison: false,
  isSameOrAfter: true
}

Expected behavior

With keepLocalTime: true, the times should remain as 07:00:00 and 08:00:00 without timezone shifting
isSameOrAfter() should return false since 07:00:00 is not after 08:00:00

Actual Behavior:

Times are shifted by timezone offset (showing as 12:00:00 and 13:00:00 in EST timezone)
isSameOrAfter() returns true incorrectly, while direct timestamp comparison (valueOf()) correctly returns false

Information

• Day.js Version v1.11.10
• OS: MacOS
• NodeJS
• Time zone: EST (UTC-5)