guisturdy/dayjs-plugin-utc

a plugin for dayjs gives dayjs the ability to operate UTC timezone

dayjs-plugin-utc's Issues

setTimezoneOffset is not a function error when using `add`ing a year

Tried adding a year to a dayjs instance extended with this plugin, and it breaks, I went ahead, forked, cloned and added a test for this project and was able to reproduce:

it('add years to current date', () => {
  const addingYears = dayjs().add(1, 'y');
  expect(addingYears.year()).toBe(dayjs().year() + 1);
})

Typescript Definitions

Hi,

I'm trying to use this in my typescript project, but there are no type definitions.

Thanks.

Support toISOString with offset

https://momentjs.com/docs/#/displaying/as-iso-string/

Dayjs don't support the keepOffset, maybe it can be done with this plugin.

`startOf` breaks offset

Hi,

Thank you for creating this plugin, but I found some issue with .startOf.

const b = dayjs.utc('2010-2-2 12:0:0').utcOffset(-450)
b.format('YYYY-MM-DD HH:mm')
// "2010-02-02 04:30"

b.hour()
// 4
b.startOf('hour').hour()
// 20 -> should be 4

b.startOf('hour').format('YYYY-MM-DD HH:mm')
// "2010-02-02 20:00" -> should be  // "2010-02-02 04:00"
b.startOf('minute').format('YYYY-MM-DD HH:mm')
// "2010-02-02 20:00" -> should be  // "2010-02-02 04:00"


b.startOf('minute').utcOffset(-450).format('YYYY-MM-DD HH:mm')
// "2010-02-02 04:30" -> works well if added `.utcOffset` again

License File not provided

Hello,

would it be possible to provide a license file, like this one: https://choosealicense.com/licenses/mit/.

Thank you!

DST issue

Daylight Savings Time seems to be an issue in the plugin.

    let utcDate = dayjs("2016-11-18:00:00:00+00:00");
    console.log(utcDate.utc().format());  // 2016-11-17T23:00:00+00:00

I'd expect 2016-11-18T00:00:00+00:00 to be the value returned.
I found that dates including and between 11/7 - 3/13 have this problem.

Or am I just missing something? (My local offset is -7, observing DST currently.)