startOf('day') is returning 23:00 of the previous day

[will3942]

Describe the bug
When executing startOf('day') it is returning an ISO String where the time is 23:00 and the date is the previous day to the original Date object.

console.log(dayjs('2020-09-22T09:41:40.935Z').startOf('day').toISOString())
=> '2020-09-21T23:00:00.000Z'

Expected behavior
I would expect it to return '2020-09-22T00:00:00.000Z'

Information

• Day.js Version: 1.9.1
• OS: MacOS 10.14.6
• Browser: Node.js 10.19.0
• Time zone: GMT+1 (BST)

[iamkun]

Hi, this is the expected result as you are in GMT+1.

You can use .toDate() to check the real date.

[will3942]

Ah, that's interesting. Thanks for the quick response!

[jefferson-liew]

console.log(dayjs().startOf('day').toISOString())

returns the local time date 2024-01-26T00:00:00.000Z

instead of 2024-01-25T16:00:00.000Z

I am in GMT +8. How can I get the same output as @will3942 ?