addDays rounds the amount without any hint in the documentation

[mwaibel-go]

There is an issue with the addDays documentation

The problem with addDays documentation

I expected

const result = addDays(new Date('2024-02-15'), 0.5)

to be Fri Feb 16 2024 12:00:00. Instead it is Thu Feb 15 2024 00:00:00.

Suggested edits

Mention that the amount parameter is rounded to the nearest integer.

This also affects all functions that are only proxies to addDays, for instance subDays.

This might also affect the other {add,sub}{period} methods.

For reference: addDays(new Date('2024-02-15'), -0.9) is equal to addDays(new Date('2024-02-15'), -1), which means that the amount is always rounded down.