📅 Range background offset bug in months with 31 days

[yehudacy]

When selecting a date range, the background highlight sometimes starts from the next day instead of the selected day.

This only occurs in months with 31 days.

Example: In August, the issue shows up on the 26th.

In October, it shows up on the 28th.

Screenshots
(one showing the expected result and one showing the issue.)

Steps to Reproduce

Open the range date picker.

Select a range in a month with 31 days (e.g., August or October).

Notice that the first day of the range is not highlighted(if you make the selected date fully rounded like in the photo it will be more clear), and the background starts from the next day.

Expected Behavior
The highlight should start from the exact selected date, not the following day.

Actual Behavior
The highlight sometimes shifts by one day in months with 31 days.

Environment

Library version: react-native-ui-datepicker 3.0.7
(Can't be on the latest cause of another issue that there is a PR on it but not merged yet)

Platform: iOS/Android

Additional context
This library has been great to use—thank you for building it!
If you have any ideas on a fix or workaround, I’d be happy to help test.

[yehudacy]

I found the code that causes the bug or in better words I found code that fixes this specific bug (without knowing the impact on other parts of the code)

in Days.js file instaid of these lines

const isFirstDayOfMonth = day.dayOfMonth === 1; const isLastDayOfMonth = day.dayOfMonth === fullDaysInMonth;

you need to replace it with

const isFirstDayOfMonth = day.number === 1 && day.isCurrentMonth; const isLastDayOfMonth = day.number === daysInCurrentMonth && day.isCurrentMonth;

and then the bug disappears @farhoudshapouran can you please look into it
thanks