add or subtract by 'date' is not working

[HDNRAY]

Describe the bug
add or subtract by 'date' is not working. by 'day' works, but then we can not use same type on all progress.

Expected behavior
add or subtract by 'date' works.

Information

• Day.js 1.8.15

[iamkun]

What's this add date stand for?

[Silver47Gin]

What's this add date stand for?

In doc, date stands for day in month and day stands for day in week. Allow for using set(x,'date') but not add(x,'date') can be confusing. Maybe make add(n,'date') and add(n,'day') have the same effect will make sense.

[HDNRAY]

What's this add date stand for?

In doc, date stands for day in month and day stands for day in week. Allow for using set(x,'date') but not add(x,'date') can be confusing. Maybe make add(n,'date') and add(n,'day') have the same effect will make sense.

Or make add(n,'day') for day in week and add(n,'date) for day in month. Each 'type' keeps the same meaning for all APIs.

[iamkun]

I'll pending this issue at present.
I do think adding add('date') will surely cause another confusion.

[franksun1988]

I found same problem.

[bogdan-nourescu]

I just ran into this problem too. I usually manipulate only date, without time, and i have to use date for set and day for add/subtract.
If add date will not be fixed/added as a feature, i would like it to be removed from the add DOCS:
https://github.com/dayjs/dayjs-website/blob/master/docs/manipulate/add.md

I read it in the docs and it seem that it will work, but, no error, no invalid date, no nothing, it just silently ignored the add call, that made me more confused and on issue hunt.

[iamkun]

@bogdan-nourescu thanks, removed. That's an error.

[innovaweb-dev]

I have same problem.

tmp = new dayjs();
tmp.add(7,'d'); // don't change the date.

// but inline, that works
tmp = new dayjs().add(7, 'd') //added 7 days.

[HDNRAY]

I have same problem.

tmp = new dayjs();

tmp.add(7,'d'); // don't change the date.



// but inline, that works

tmp = new dayjs().add(7, 'd') //added 7 days.

not same. Your problem is due to dayjs is immutable.