.month() resets date property to 1 when in +00:00 UTC timezone

[JohnBDonner]

Describe the bug
When using the timezone plugin, if the timezone is in UTC, the month() setter function also resets the date property to 1. When the timezone is in any other UTC offset besides 0, or if no .tz is applied, the date stays the same.

import dayjs from 'dayjs'
import timezone from 'dayjs/plugin/timezone'

dayjs.extend(timezone)

const d = dayjs('2022-04-19T03:00:00-02:00').tz('America/Godthab')
console.log(dayjs(d).month(3).format())                // => 2022-04-19T03:00:00-02:00
console.log(dayjs(d).month(3).date(d.date()).format()) // => 2022-04-19T03:00:00-02:00

const dUtc = dayjs(d).tz('GMT')
console.log(dayjs(dUtc).month(3).format())                   // => 2022-04-01T10:00:00Z
console.log(dayjs(dUtc).month(3).date(dUtc.date()).format()) // => 2022-04-19T10:00:00Z

Expected behavior
I'd expect month() to only change the month (and only reset the date() property if it's invalid, such as 31 into a 30-day month).

Information

• Day.js Version: v1.10.7
• OS: MacOS Monteray 12.3
• Browser: Brave 1.36.122
• Time zone: GMT-05:00 CDT (Central Daylight Time)